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Home , 2014 in paleontology, Dakota Hogback, Dinosaur Beds, Geology of Colorado, Hogback (geology), Jelm Formation

PALEONTOLOGICAL TECHNICAL REPORT: NORTHERN INTEGRATED SUPPLY PROJECT, PROPOSED U.S. HIGHWAY 287 REALIGNMENT LARIMER COUNTY,

Prepared for:

ERO Resources Corporation 1842 Clarkson Street , CO 80218

Prepared by:

Paul C. Murphey, Ph.D. and David Daitch, M.S. Rocky Mountain 4614 Lonespur Court Oceanside, CA 92056 303-514-1095; 760-758-4019 www.rockymountainpaleontology.com

Prepared under State of Colorado Paleontological Permit 2006-5

Revised October 2014 TABLE OF CONTENTS 1.0 SUMMARY ...... 1 2.0 INTRODUCTION ...... 3 2.1 Definition and Significance of Paleontological Resources ...... 3 3.0 METHODS ...... 5 4.0 LAWS, ORDINANCES, REGULATIONS, AND STANDARDS ...... 6 4.1 Federal...... 6 4.2 State...... 8 4.3 County ...... 8 4.4 City ...... 8 4.5 Private Lands ...... 9 4.6 Permits and Approvals ...... 9 5.0 RESOURCE ASSESSMENT CRITERIA ...... 10 5.1 Potential Yield Classification ...... 10 6.0 PALEONTOLOGICAL RESOURCE ASSESSMENT ...... 11 7.0 AFFECTED ENVIRONMENT ...... 12 7.1 Geology and Paleontology ...... 12 7.1.1 Lykins Formation ...... 17 7.1.2 Undivided Jelm and Sundance Formations...... 17 7.1.3 ...... 17 7.1.4 Dakota Group ...... 18 7.1.5 Benton Group ...... 19 7.1.6 ...... 19 8.0 EXISTING CONDITIONS ...... 21 8.1 Museum Record Searches ...... 21 8.2 Field Survey ...... 22 9.0 RECOMMENDATIONS ...... 24 10.0 IMPACTS ANALYSIS ...... 25 10.1 Direct Impacts ...... 25 10.2 Indirect Impacts ...... 26 10.3 Cumulative Impacts ...... 26 11.0 MITIGATION MEASURES ...... 27 12.0 REFERENCES ...... 30

NISP EIS – Paleontological Resources i TABLES Table 1. Summary of Paleontological Laws, Ordinances, Regulations and Standards Applicable to the NISP U.S. 287 Realignment...... 9 Table 2. Summarized Paleontological Sensitivities of Geologic Units within the APE for the Preferred NISP U.S. 287 Western Alternative using the PFYC System (Map Abbreviations are from Braddock et al., 1988a, 1988b)...... 11 Table 3. Previously Recorded Fossil Localities from within and Nearby the NISP Study Area. UCM, University of Colorado Museum of Natural History...... 22 Table 4. Fossil Localities Discovered within the Field Survey for the Western Alternative of the NISP U.S. 287 Realignment. Fossil locality coordinates are provided in the confidential appendix...... 23

FIGURES Figure 1. Aerial Photograph of a Portion of the APE for the NISP Showing the U.S. 287 Western and Northern Realignment Alternative Corridors...... 4 Figure 2. Geologic Map Showing the Approximate Location of the Southern Portion of the NISP U.S. 287 Western Alternative Northwest of Fort Collins, Larimer County, Colorado (from Braddock et al., 1988a)...... 13 Figure 3. Geologic Map Showing the Approximate Location of the Northern Portion of the NISP U.S. 287 Western Alternative Alignment Northwest of Fort Collins, Larimer County, Colorado (from Braddock et al., 1988a)...... 14 Figure 4. Geologic Map Showing the Approximate Location of the Southern Portion of the NISP U.S. 287 Northern Alternative Alignment Northwest of Fort Collins, Larimer County, Colorado (from Braddock et al., 1988a)...... 15 Figure 5. Geologic Map Showing the Approximate Location of the Northern Portion of the NISP U.S. 287 Northern Alternative Alignment Northwest of Fort Collins, Larimer County, Colorado (from Braddock et al., 1988b)...... 16

APPENDICES Appendix 1 Confidential Fossil Locality Data ...... 34

NISP EIS – Paleontological Resources ii 1.0 SUMMARY

This is a paleontological assessment of two alternative realignments of U.S. Highway 287 (U.S. 287) for the Northern Integrated Supply Project (NISP). The western and northern alignment alternatives are located within portions of sections 5-8, 17-20, and 29-32, T. 9 N., R. 69 W., and sections 5-8, and 17-18, T. 8 N., R. 69 W. (sixth Principal Meridian), on the USGS Laporte and Livermore 7.5’ topographic quadrangles in Larimer County, Colorado (see Figure 1). Although this report presents the results of the literature and record searches conducted for both realignment alternatives, the field survey included only the preferred alternative of the Colorado Department of Transportation (CDOT), the western alternative. This alternative, which is approximately seven miles long, was surveyed for paleontological resources on January 23 and April 16, 2006. The survey corridor was approximately 200 feet wide (100 feet on either side of centerline). For this study, the Area of Potential Effect (APE) is defined as both the western and northern alternatives, for which literature and museum record searches were conducted. The survey corridor is defined as the preferred alignment for which a pedestrian field survey was conducted, and the width of the corridor was designed to encompass the maximum area of surface disturbance associated with highway construction.

The paleontological sensitivities of the geologic units within the APE for the U.S. 287 western and northern realignment alternatives associated with NISP were evaluated by reviewing scientific and technical literature, geologic mapping and museum records. Based on the geologic mapping of Braddock et al. (1988a, 1988b), the study area contains six bedrock geologic units ranging in age from to . These units include, from stratigraphically lowest to highest, the Upper Permian to Lower Lykins Formation, the Upper Triassic and Upper and Middle undivided, the Upper Jurassic Morrison Formation, the Lower Cretaceous Dakota Group, the Lower Cretaceous Benton Group, and the Upper Cretaceous Niobrara Formation. All of these units are known to contain of various taxonomic affinities and abundances across their distribution.

At least four previously recorded fossil localities occur within or nearby the APE for NISP western and northern alignment alternatives. Fossil localities are sites where fossils have been previously documented. However, none of these are located within the western alignment. These include University of Colorado Museum localities 86050, from which fossils were collected from the Morrison Formation; 87092, from which sharks teeth were collected from the Smoky Hill Member of the Niobrara Formation; and 88015, from which inoceramid clams were collected from the South Platte Formation of the Dakota Group. Locality 86050 is also the type locality for a species of freshwater described by Dunagan (1999). Waage (1955) reported plesiosaur vertebrae in the Dakota Group northeast of Laporte and north of the study area. An approximately 60% complete specimen of the fossil from the Niobrara Formation at the cement quarry located at the southern end of the realignment alternatives along the existing Highway 287 right-of-way was reported to exist by a commenter on the NISP Draft Environmental Impact Statement (DEIS) (Warnock, 2008). This specimen was reportedly on display at the Fort Collins Museum of Discovery in Fort Collins (Warnock,

NISP EIS – Paleontological Resources 1 2008). However, as of August 21, 2014, the specimen was not among the six fish fossils the museum had in its collections (personal communication with the Fort Collins Museum of Discovery, 2014), its whereabouts were unknown, and the locality description for this specimen could not be confirmed. Additionally, three fossil localities were recorded during the field survey of the western alternative for this study, although no fossils were collected. Numerous additional fossil localities have been recorded in the same geologic units that occur within the study area elsewhere in Colorado and adjacent states.

Detailed information regarding the amount of bedrock disturbance required for highway realignment was not available at the time of this analysis. However, based on the project description, it is anticipated that significant bedrock disturbance will occur during construction of the western alternative. In combination with the known paleontological sensitivities of the geologic units within the study area and the presence of known localities in the immediate vicinity which have produced scientifically significant fossils, adverse impacts on significant paleontological resources are likely to occur during highway construction within the western alternative. Potential adverse impacts on paleontological resources within the study area can be reduced to below the level of significance with paleontological mitigation, including construction monitoring. Prior to construction, it is recommended that the CDOT Staff Paleontologist examine the final design plans and determine the extent of bedrock impact and the scope of paleontological monitoring required.

NISP EIS – Paleontological Resources 2 2.0 INTRODUCTION

This paleontological resources assessment is an evaluation of potential impacts on scientifically significant nonrenewable paleontological resources that could result from construction-related ground disturbance within the APE for the proposed U.S. 287 realignment alternatives associated with NISP. The U.S. 287 realignment study area is located on the USGS Laporte and Livermore 7.5’ topographic quadrangles northwest of the City of Fort Collins in Larimer County, Colorado (see Figure 1). This report presents the results of the literature and record searches conducted for U.S. 287 northern and western realignment alternatives, and the field survey conducted for the western alternative, CDOT’s preferred alternative. The western alternative is approximately seven miles long, and is underlain by potentially fossiliferous strata of the Lykins Formation, undivided Jelm and Sundance formations, Morrison Formation, Dakota Group, Benton Group, and Niobrara Formation. The northern alternative is approximately 7.5 miles long, and crosses the same bedrock geologic units.

2.1 Definition and Significance of Paleontological Resources

Paleontology is a multidisciplinary that combines elements of geology, biology, chemistry, and physics in an effort to understand the history of life on . Paleontological resources, or fossils, are the remains, imprints, or traces of once-living preserved in rocks and sediments. These include mineralized, partially mineralized, or unmineralized bones and teeth, soft tissues, shells, wood, leaf impressions, footprints, , and microscopic remains. The fossil record is the only evidence that life on earth has existed for more than 3.6 billion years. Fossils are considered nonrenewable resources because the organisms they represent no longer exist. Thus, once destroyed, a fossil can never be replaced. Fossils are important scientific and educational resources because they are used to:

 Study the phylogenetic relationships between extinct organisms, as well as their relationships to modern groups.  Elucidate the taphonomic, behavioral, temporal, and diagenetic pathways responsible for fossil preservation, including the biases inherent in the fossil record.  Reconstruct ancient environments, climate change, and paleoecological relationships.  Provide a measure of relative geologic dating which forms the basis for biochronology and biostratigraphy, and which is an independent and corroborating line of evidence for isotopic dating.  Study the geographic distribution of organisms and tectonic movements of land masses and ocean basins through time.  Study patterns and processes of evolution, , and speciation.  Identify past and potential future human-caused effects to global environments and climates.

NISP EIS – Paleontological Resources 3

Figure 1. Aerial Photograph of a Portion of the APE for the NISP Showing the U.S. 287 Western and Northern Realignment Alternative Corridors.

NISP EIS – Paleontological Resources 4 3.0 METHODS

The purpose of this study is to evaluate the paleontological sensitivities of the geologic units within the APE for U.S. 287 western and northern realignment alternatives within the overall footprint of the NISP by researching their known fossil potential and paleontological significance, and by determining the number and significance of fossil localities within the study area and in the same geologic units elsewhere. The scope of the study included a review of relevant scientific literature, geologic maps, and museum records, as noted in the references. The museums included in the record search were the University of Colorado Museum (UCM), the Denver Museum of and Science (DMNS), the University of Geology Museum, Colorado State University, and the Fort Collins Museum of Discovery. The University of Wyoming Museum, Colorado State University, and the Fort Collins Museum of Discovery have no institutional paleontological records within the APE. The paleontological evaluation procedures for this study were conducted in accordance with Society of Vertebrate Paleontology (SVP) (1995) guidelines by qualified and permitted paleontologists (State of Colorado Paleontological Permit 2006-5). This study was conducted at the request of CDOT, the U.S. Army Corps of Engineers (Corps), and ERO Resources Corporation, Denver, Colorado (ERO).

The western alternative (see Figure 1) field survey corridor was 200 feet wide (100 feet on either side of centerline). The field survey for this study was conducted on January 23 and April 16, 2006, and consisted of an inspection of the APE for 1) surface fossils, 2) exposures of potentially fossiliferous rocks, and 3) areas in which fossiliferous rocks or younger potentially fossiliferous surficial deposits could be exposed or otherwise impacted during construction-related ground disturbance. For paleontological surveys in general, areas where geologic units of moderate and high paleontological sensitivities are exposed are subject to a 100% pedestrian inspection, and areas with exposures of low sensitivity deposits are evaluated based on the professional judgment of the principal investigator. Areas with no paleontological sensitivity are not inspected. A field survey was not conducted for the northern alternative because it was not selected as CDOT’s preferred alternative and therefore ground disturbing activities would not occur along that alignment.

NISP EIS – Paleontological Resources 5 4.0 LAWS, ORDINANCES, REGULATIONS, AND STANDARDS

Fossils are classified as nonrenewable scientific resources and are protected by various laws, ordinances, regulations, and standards (LORS) across the country. Professional standards for the assessment and mitigation of adverse impacts to paleontological resources have been established by the SVP (1995). This paleontological study was conducted in accordance with the LORS, which are applicable to paleontological resources within the APE for the NISP U.S. 287 realignment alternatives (see Table 1). Applicable federal, state, county, and city LORS are summarized below.

4.1 Federal

The National Environmental Policy Act of 1969, as amended (NEPA) (Pub. L. 91-190, 42 U.S.C. 4321-4347, January 1, 1970, as amended by Pub. L. 94-52, July 3, 1975, Pub. L. 94-83, August 9, 1975, and Pub. L. 97-258 § 4(b), Sept. 13, 1982). NEPA recognizes the continuing responsibility of the federal government to “preserve important historic, cultural, and natural aspects of our national heritage...” (Sec. 101 [42 U.S.C. § 4321]) (#382).

The goal of the NEPA process is to make informed decisions regarding environmental issues. Under NEPA, the federal government requires that: a) all federal agencies consider the environmental impacts of proposed actions; b) the public be informed of the potential environmental impacts of proposed actions; and c) the public be involved in planning and analysis relevant to actions that impact the environment.

The Corps Regulatory Program implements NEPA in accordance with procedures described in 33 CFR 325, Appendix B. The Corps considers potential impacts to paleontological resources via the public interest review evaluation described in 33 CFR 320.4 as follows:

(a) Public interest review. (1) The decision whether to issue a permit will be based on an evaluation of the probable impacts, including cumulative impacts, of the proposed activity and its intended use on the public interest. Evaluation of the probable impact which the proposed activity may have on the public interest requires a careful weighing of all those factors which become relevant in each particular case. The benefits which reasonably may be expected to accrue from the proposal must be balanced against its reasonably foreseeable detriments. The decision whether to authorize a proposal, and if so, the conditions under which it will be allowed to occur, are therefore determined by the outcome of this general balancing process. That decision should reflect the national concern for both protection and utilization of important resources. All factors which may be relevant to the proposal must be considered including the cumulative effects thereof: among those are conservation, economics, aesthetics, general environmental concerns, wetlands, historic properties, fish and wildlife values, flood hazards, floodplain values, land use, navigation, shore and accretion, recreation, water supply and conservation, water quality, energy needs, safety, food and fiber production, mineral needs, considerations of property ownership and, in general, the needs and welfare of the people. For activities involving 404 discharges, a permit will be denied if the discharge that would be

NISP EIS – Paleontological Resources 6 authorized by such permit would not comply with the Environmental Protection Agency’s 404(b)(1) guidelines. Subject to the preceding sentence and any other applicable guidelines and criteria (see §§320.2 and 320.3), a permit will be granted unless the district engineer determines that it would be contrary to the public interest.

(e) Historic, cultural, scenic, and recreational values. Applications for DA permits may involve areas which possess recognized historic, cultural, scenic, conservation, recreational or similar values. Full evaluation of the general public interest requires that due consideration be given to the effect which the proposed structure or activity may have on values such as those associated with wild and scenic rivers, historic properties and National Landmarks, National Rivers, National Wilderness Areas, National Seashores, National Recreation Areas, National Lakeshores, National Parks, National Monuments, estuarine and marine sanctuaries, archeological resources, including Indian religious or cultural sites, and such other areas as may be established under federal or state law for similar and related purposes. Recognition of those values is often reflected by state, regional, or local land use classifications, or by similar federal controls or policies. Action on permit applications should, insofar as possible, be consistent with, and avoid significant adverse effects on the values or purposes for which those classifications, controls, or policies were established.

Mitigation requirements for unavoidable project impacts are also described in 33 CFR 320.4:

(r) Mitigation.1 (1) Mitigation is an important aspect of the review and balancing process on many Department of the Army permit applications. Consideration of mitigation will occur throughout the permit application review process and includes avoiding, minimizing, rectifying, reducing, or compensating for resource losses. Losses will be avoided to the extent practicable. Compensation may occur on-site or at an off-site location. Mitigation requirements generally fall into three categories.

(i) Project modifications to minimize adverse project impacts should be discussed with the applicant at pre-application meetings and during application processing. As a result of these discussions and as the district engineer’s evaluation proceeds, the district engineer may require minor project modifications. Minor project modifications are those that are considered feasible (cost, constructability, etc.) to the applicant and that, if adopted, will result in a project that generally meets the applicant’s purpose and need. Such modifications can include reductions in scope and size; changes in construction methods, materials or timing; and operation and maintenance practices or other similar modifications that reflect a sensitivity to environmental quality within the context of the work proposed. For example, erosion control features could be required on a fill project to reduce sedimentation impacts or a pier could be reoriented to minimize navigational problems even though those projects may satisfy all legal requirements (paragraph (r)(1)(ii) of this section) and the public interest review test (paragraph (r)(1)(iii) of this section) without such modifications.

1This is a general statement of mitigation policy which applies to all Corps of Engineers regulatory authorities covered by these regulations (33 CFR parts 320-330). It is not a substitute for the mitigation requirements necessary to ensure that a permit action under section 404 of the Clean Water Act complies with the section 404(b)(1) Guidelines. There is currently an interagency Working Group formed to develop guidance on implementing mitigation requirements of the Guidelines.

NISP EIS – Paleontological Resources 7 (ii) Further mitigation measures may be required to satisfy legal requirements. For Section 404 applications, mitigation shall be required to ensure that the project complies with the 404(b)(1) Guidelines. Some mitigation measures are enumerated at 40 CFR 230.70 through 40 CFR 230.77 (Subpart H of the 404(b)(1) Guidelines).

(iii) Mitigation measures in addition to those under paragraphs (r)(1) (i) and (ii) of this section may be required as a result of the public interest review process. (See 33 CFR 325.4(a).) Mitigation should be developed and incorporated within the public interest review process to the extent that the mitigation is found by the district engineer to be reasonable and justified. Only those measures required to ensure that the project is not contrary to the public interest may be required under this subparagraph.

CFR Title 43

Under the Code of Federal Regulations (CFR) Title 43, Section 8365.1-5, the collection of scientific resources, including vertebrate fossils, is prohibited without a permit. Except where prohibited, individuals are also authorized to collect some fossils for their personal use. The use of fossils found on federal lands for commercial purposes is also prohibited.

4.2 State

Colorado Historical, Prehistorical and Archaeological Resources Act of 1973 (CRS 24-80-401 to 411, and 24-80-1301 to 1305). Defines permitting requirements and procedures for the collection of prehistoric resources, including paleontological resources, on state lands, and actions that should be taken in the event resources are discovered in the course of state-funded projects and on state-owned/administered lands. Based on this legislation, the CDOT requests assessments on state-owned/administered lands that have the potential to contain significant paleontological resources, and monitoring/mitigation during ground disturbance in these areas. This paleontological assessment was requested by the CDOT because CDOT is a cooperating agency for NISP and must fulfill the FHWA’s NEPA requirements, and CDOT will own the right-of-way for the proposed realignment for U.S. 287.

4.3 County

There are no Larimer County LORS that specifically address potential adverse impacts on paleontological resources. Therefore, no county-level protections of paleontological resources pertain to the NISP U.S. 287 realignment.

4.4 City

No city-level protections of paleontological resources pertain to the NISP U.S. 287 realignment.

NISP EIS – Paleontological Resources 8 4.5 Private Lands

There are no LORS applicable to paleontological resources which occur on privately owned lands in the State of Colorado.

Table 1. Summary of Paleontological Laws, Ordinances, Regulations and Standards Applicable to the NISP U.S. 287 Realignment.

Agency/Owner Pertinent Paleontological LORS Federal Assessment requested by the Corps State Assessment requested by CDOT under CHPA County None City None Private None

4.6 Permits and Approvals

If paleontological mitigation is requested by the CDOT, the project paleontologist and other paleontological personnel would be required to possess a State of Colorado paleontological permit. The paleontological mitigation program would need approval by the CDOT staff paleontologist, who would also review and approve the final mitigation report. All fossils collected during mitigation would be required to be housed in an approved repository such as the Denver Museum of Nature and Science or the University of Colorado Museum where they could be studied and/or displayed.

NISP EIS – Paleontological Resources 9 5.0 RESOURCE ASSESSMENT CRITERIA

The paleontological sensitivities of each geologic unit within the APE for the NISP U.S. 287 western and northern realignment alternatives were evaluated using the Potential Fossil Yield Classification (PFYC) system. This system is presented below.

5.1 Potential Fossil Yield Classification

The PFYC was developed by the U.S. Forest Service (1996). It was intended to be used by professional paleontologists using paleontologic and geologic data supplemented by museum and library research, and it is becoming more widely used by paleontologists and government agencies. For this study, the PFYC has been modified to explicitly include fossil plants:

 Class 1: Igneous and metamorphic geologic units (excluding tuffs) that are not likely to contain recognizable fossil remains. Ground-disturbing activities will not require mitigation except in rare circumstances.  Class 2: Sedimentary geologic units that are not likely to contain vertebrate fossils or scientifically significant invertebrate (or plant) fossils. Ground-disturbing activities are not likely to require mitigation.  Class 3: Fossiliferous sedimentary geologic units where fossil content varies in significance, abundance, and predictable occurrence. Ground-disturbing activities will require sufficient mitigation to determine whether significant paleontological resources occur in the area of a proposed action. Mitigation beyond initial findings will range from no further action necessary to full and continuous monitoring of significant localities during the action.  Class 4: Class 4 geologic units are Class 5 units that have lowered risks of human-caused adverse impacts and/or lowered risk of natural degradation. Proposed ground-disturbing activities will require assessment to determine whether significant paleontological resources occur in the area of a proposed action and whether the action will impact the resources. Mitigation beyond initial findings will range from no further mitigation necessary to full and continuous monitoring of significant localities during the action. This classification will often not be applied until after on-the-ground assessments are made.  Class 5: These are highly fossiliferous geologic units that regularly and predictably produce vertebrate fossils and/or scientifically significant invertebrate (or plant) fossils, and that are at high risk of natural degradation and/or human-caused adverse impacts. These areas are likely to be poached. Mitigation of ground-disturbing activities is required and may be intense. Areas of special interest and concern should be designated and intensely managed.

NISP EIS – Paleontological Resources 10 6.0 PALEONTOLOGICAL RESOURCE ASSESSMENT

Ground disturbance associated with the construction activities within the preferred NISP U.S. 287 western alternative will impact six geologic units ranging in age from late Permian to . All of these units have the potential to contain fossils of varying taxonomic affinity, scientific significance and density across their distribution based on museum records (UCM and DMNS, unpublished paleontological data), the scientific literature, and previous paleontological assessments and surveys along the Colorado . The paleontological sensitivities of these units were evaluated using the PFYC, which was presented in Section 5.1, and the results are summarized in Table 2. The geology and paleontology of these units are discussed in Section 7.0 of this report.

Table 2. Summarized Paleontological Sensitivities of Geologic Units within the APE for the Preferred NISP U.S. 287 Western Alternative using the PFYC System (Map Abbreviations are from Braddock et al., 1988a, 1988b). Map Geologic Unit Age Typical Fossils PFYC Abbreviations Niobrara Formation Kn, Kns, Knf Late Cretaceous Locally abundant marine Class 3 invertebrates, less common terrestrial and marine vertebrates (especially Member) Benton Group Kcgm Early Scarce vertebrates (marine Class 3 Cretaceous and fish), locally abundant marine invertebrates Dakota Group Kd, Ksf, Ksmp, Early Scarce vertebrates, locally Class 3 Kl Cretaceous common marine invertebrates, terrestrial plants, and trace fossils Morrison Formation Jm Locally common terrestrial Class 5 vertebrates (especially ), invertebrates, plants, and trace fossils Undivided Sundance and JTsj Jelm: scarce fossils including Class 3 Jelm formations (Jelm), middle bone fragments and wood. and late Jurassic Sundance: Marine vertebrates (Sundance) and invertebrates Lykins Formation Tr?Pl, Trla Late Permian to Stromatolites Class 2

NISP EIS – Paleontological Resources 11 7.0 AFFECTED ENVIRONMENT

The front range foothills and adjacent region of Colorado is well known for its geologic history and paleontologic importance. Scientists working in this area have conducted numerous geological and paleontological studies, some of which are now considered classic works. Many important fossil specimens, including numerous holotypes, have been collected in this region. These include the type specimens of the dinosaurs, armatus, , , and Apatosaurus ajax, which were collected during the late nineteenth century from historic quarries near the town of Morrison. These and many other fossils are now housed in museums in Colorado and around the world. The geology and paleontology of the region is scientifically important because, for example, it records the erosion of the ancestral , development of a vast interior seaway which covered much of central North America, extinction of the dinosaurs at the end of the Cretaceous Period, development of tropical rainforest ecosystems and evolutionary radiation of mammals during the , and the environments and which lived in the region during the ice ages. Today, these events in earth’s history, together with evidence of the diverse organisms that inhabited ancient Colorado, can be viewed at many well-known locations in the Denver area. These include, but are not limited to, the Denver Museum of Nature and Science, University of Colorado Museum, Morrison Natural History Museum, Red Rocks Park, the Dakota and I-70 Roadcut, and Dinosaur .

7.1 Geology and Paleontology

In the vicinity of the study area, to units are tilted upward and dip to the east, creating a series of resistant hogbacks upon which bedrock is typically well exposed. The bedrock units are locally mantled by deposits of colluvium, which have low paleontological sensitivity and will not be considered further in this report. Based on the geologic mapping of Braddock et al. (1988a, 1988b), the study area contains six geologic units. These include, from stratigraphically lowest to highest: the Upper Permian and Lower Triassic Lykins Formation, undivided Upper Triassic Jelm Formation and Upper and Sundance Formation, Upper Jurassic Morrison Formation, Lower Cretaceous Dakota Group (South Platte and Lytle formations), Lower Cretaceous Benton Group (, Greenhorn , , and ), and Upper Cretaceous Niobrara Formation (Smoky Hill Shale Member and Fort Hays Limestone Member). Indeck and Wallace (1988) discussed the geology and paleontology of the U.S. 287 corridor in this area in detail in their unpublished report of a paleontological monitoring and salvage project conducted during the 1986-1987 realignment of U.S. 287. Figures 2 and 3 show the distribution of the geologic units within the NISP U.S. 287 preferred western alternative, for which the field survey was conducted. The following is a general discussion of the geology and paleontology of these units. Figures 4 and 5 show the distribution of the geologic units within the NISP U.S. 287 northern alternative, which was included in the scientific literature and museum record search conducted for this study, but was not field surveyed.

NISP EIS – Paleontological Resources 12

Figure 2. Geologic Map Showing the Approximate Location of the Southern Portion of the NISP U.S. 287 Western Alternative Northwest of Fort Collins, Larimer County, Colorado (from Braddock et al., 1988a).

NISP EIS – Paleontological Resources 13

Figure 3. Geologic Map Showing the Approximate Location of the Northern Portion of the NISP U.S. 287 Western Alternative Alignment Northwest of Fort Collins, Larimer County, Colorado (from Braddock et al., 1988a).

NISP EIS – Paleontological Resources 14

Figure 4. Geologic Map Showing the Approximate Location of the Southern Portion of the NISP U.S. 287 Northern Alternative Alignment Northwest of Fort Collins, Larimer County, Colorado (from Braddock et al., 1988a).

NISP EIS – Paleontological Resources 15

Figure 5. Geologic Map Showing the Approximate Location of the Northern Portion of the NISP U.S. 287 Northern Alternative Alignment Northwest of Fort Collins, Larimer County, Colorado (from Braddock et al., 1988b).

NISP EIS – Paleontological Resources 16 7.1.1 Lykins Formation The late Permian and early Triassic Lykins Formation is at least partially equivalent with the Chugwater, Dinwoody, Thanes, Spearfish, Jelm, Ankareh, Woodside, Lykins, Chinle, and Dolores formations, and the Glen Canyon and Dockum groups. In the vicinity of the study area, the late Permian and early Triassic Lykins Formation is comprised of red and reddish-brown siltstone and fine-grained sandstone containing several carbonate beds, and is approximately 700 feet thick (Braddock et al., 1988a, 1988b). The Lykins Formation has been subdivided into four members: the Forelle Limestone, Bergen Shale, Falcon Limestone, and Harriman Shale. Paleontologically, it contains few fossils, and is best known for its algal stromatolites. Rare fossil bone has also been discovered (unpublished UCM paleontological data). Because of its scarce fossils, the Lykins Formation is considered to have low paleontological sensitivity, and was classified as Class 2 for this analysis. The distribution of this unit within the survey corridor is shown on Figures 2 and 3 (Tr?Pl, Trla).

7.1.2 Undivided Jelm and Sundance Formations The Red Draw Member of the Jelm Formation is unconformably overlain by the Sundance Formation within the project area. Varying from 90 to 134 feet, the Red Draw Member is composed of orange-pink and reddish-brown cross-bedded fine-grained calcareous sandstone. The unconformity is marked by the presence of conspicuous chert pebbles (Braddock et al., 1988a, 1988b). The Sundance Formation is subdivided into the conformable Canyon Springs, Pine Butte, and Windy Hill members, from lowest to highest. The Canyon Springs Member is composed of approximately 36 feet of orange-pink and reddish-brown, fine- to medium-grained, cross-bedded, calcareous sandstone (Braddock et al., 1988a, 1988b). The Pine Butte Member consists of approximately 13 feet of massive- to tabular-bedded, fine-grained, gray to white sandstone. The Windy Hill Member is composed of approximately 13 feet of flat-bedded, light gray, fine-grained sandstone and gray clay shale (Braddock et al., 1988a, 1988b).

Few fossils have been reported from the Jelm Formation, which is of nonmarine origin. The University of Wyoming Geological Museum has in its collections an isolated and unidentified tooth from the unit. Unidentifiable bone fragments in a conglomerate within the Jelm Formation were reported by Pipiringos (1953). Any additional fossil discoveries would be of great importance to efforts to constrain the age of this unit.

The Sundance Formation, which is of marine origin, is widely distributed in , Wyoming, North Dakota, and Colorado; and is more fossiliferous than the Jelm Formation. It has yielded marine vertebrate fossils including reptiles and , as well as marine mollusks and trace fossils. Drake and Wahl (1994) reported numerous juvenile and adult individuals of and plesiosaurs which were quarried from the Sundance Formation in Natrona County, Wyoming. Fishes, sea urchins, sea stars, and lobsters have also been reported, and some specimens exhibit exceptional preservation (Schaeffer and Patterson, 1984). For this analysis, the undivided Jelm and Sundance formations were classified as Class 3, and their distribution within the survey corridor is shown in Figures 2 and 3 (JTsj).

7.1.3 Morrison Formation The widely distributed and highly fossiliferous Upper Jurassic Morrison Formation was deposited in a combination of fluvial and lacustrine environments in warm, humid climatic

NISP EIS – Paleontological Resources 17 conditions after the regression of an inland sea (Peterson, 1972). It is interpreted to contain numerous unconformities. Lithologically, the Morrison Formation is composed of variegated red, green, and gray mudstone and claystone, with tan sandstone and siltstone and gray limestone (Braddock et al., 1988a, 1988b; Bryant et al., 1981). In much of its distribution in Colorado, it has been locally subdivided into members including the Brushy Basin, Westwater Canyon, Recapture Creek, Salt Wash, and Bluff Sandstone. In the vicinity of the study area, the Morrison Formation is approximately 320 feet thick (Braddock et al., 1988a, 1988b). The Morrison Formation is well known for the large number of dinosaur remains that are preserved within it, including many historically important holotypes now stored in museums around the world. Historically important fossil localities within the Morrison Formation are numerous, and include Como Bluff in Wyoming, Dinosaur National Monument in Utah, and localities near Morrison (the type locality of the Morrison Formation) and Canon City, Colorado, among others.

Dinosaur bones, teeth, and fragments of fossil wood are perhaps the most common Morrison Formation fossils, although an extremely diverse fish, nondinosaur reptilian, mammalian, plant, and trace fossil assemblage has also been documented. In addition to rich dinosaur bone beds with articulated and disarticulated remains that are often very well preserved, the Morrison Formation has produced a diverse assemblage of small mammals and nondinosaurian reptiles, dinosaur eggs, trackways, and plants. A new and species of the oldest yet described freshwater sponge was collected from a limestone bed in the Morrison Formation along U.S. 287 north of Laporte (UCM L. 86050), and described by Dunagan (1999). The geology and paleontology of the Morrison Formation has been studied extensively (Armstrong and Kihm, 1980; Armstrong and McReynolds, 1987; Bilbey, 1992; Carpenter, 1979; Dodson et al., 1980, Peterson, 1988; Tidwell, 1990; and numerous other references), and it has produced the greatest diversity of Jurassic-age fossils of any rock unit in the world (Breithaupt, 1994). The Morrison Formation is highly sensitive and was classified as Class 5 for this analysis. Its distribution within the survey corridor is shown in Figures 2 and 3 (Jm).

7.1.4 Dakota Group The Lower Cretaceous Dakota Group unconformably overlies the Morrison Formation. Within the NISP study area and elsewhere in Colorado, it has been subdivided into the basal which is approximately 80 feet thick, overlain by the South Platte Formation which is about 210 feet thick. The South Platte Formation has been further subdivided into the Plainview Sandstone Member, the middle shale member, and the first sandstone member (from lowest to highest). The Lytle Formation is composed of gray to tan, coarse-grained conglomeratic sandstone, and blocky weathering, multicolored, noncarbonaceous mudstone. The Plainview Sandstone Member is composed of gray to tan, thin-bedded, fine-grained, carbonaceous sandstone. The middle shale member consists of dark gray carbonaceous shale, thin bentonite, and thin gray siltstone and sandstone beds. The first sandstone member is composed of gray to tan, well-sorted, fine- to medium-grained sandstone, and its basal contact has been interpreted as an unconformity (Braddock et al., 1988a, 1988b; Ellis et al., 1987; Waage, 1955).

Deposited during the first major transgression of the Cretaceous Interior Seaway in beach, estuarine, and other proximal shoreline depositional environments, rocks of the Dakota Group contain a moderately diverse fossil fauna and flora. The unit is well known for its fossil footprints and other trace fossils, and also contains scattered bones and locally well-preserved

NISP EIS – Paleontological Resources 18 plant remains. Dinosaur track sites from near the top of the Dakota Group have been reported from numerous localities in Colorado. Lockley et al. (1992) described several dozen dinosaur track sites along the Colorado Front Range; and the southern high plains of Colorado, Oklahoma, and New . According to these authors, all of these track sites occur in a stratigraphic interval that is less than 30 feet thick. This interval is referred to as a “megatracksite” and it is estimated that this track-bearing complex, which includes dinosaur, crocodile, and bird tracks, covers an area of 80,000 square kilometers. Waage (1955) cited plesiosaur vertebrae in the Dakota Group to the north of the NISP study area in T. 10 N., R. 69 W. Dakota fossils have been the subject of numerous paleontologic studies (Chamberlain, 1976; Elliot and Nations, 1998; Lockley, 1987, 1990, 1992; Mehl, 1931; Snow, 1887; Rushforth, 1971; Waage and Eicher, 1960; Young, 1960). The Dakota Sandstone was classified as Class 3 for this analysis and its distribution within the survey corridor is shown in Figures 2 and 3 (Kd, Ksf, Ksmp, Kl).

7.1.5 Benton Group The Lower Cretaceous Benton Group, also referred to as the Carlile Shale, has been subdivided, from stratigraphically lowest to highest, into the Mowry Shale, the Graneros Shale, the , and the Carlile Shale. The Mowry Shale consists of approximately 20 feet of white-weathering siliceous shale. The Graneros Shale consists of dark gray to grayish- black siltstone and claystone, and is approximately 150 feet thick. The Greenhorn Limestone consists of approximately 250 feet of interbedded dark-gray limestone and olive gray calcareous silty claystone and siltstone. The Carlile Shale consists of approximately 75 feet of olive gray silty claystone and sandy siltstone (Braddock et al., 1988a, 1988b). These rocks are interpreted to have been mostly deposited in a nearshore marine environment and record transgressions and regressions of the .

Rocks of the Benton Group (Carlile Shale) contain locally abundant marine invertebrates, especially bivalves and ammonites. Vertebrate fossils are more rarely preserved in these strata than in rocks of other Cretaceous-age rock units such as the Niobrara Formation and . Well-preserved fish fossils have been discovered in the Carlile Shale in . Isolated and mostly poorly preserved plesiosaur remains have also been recovered. The Benton Group was classified as Class 3 for this analysis and its distribution within the survey corridor is shown in Figures 2 and 3 (Kcgm).

7.1.6 Niobrara Formation Like the Dakota and Benton groups, the Niobrara Formation is a stratigraphically complex geologic unit. It has been subdivided into the Fort Hays Limestone Member and the conformably overlying Smoky Hill Shale Member, and is stratigraphically equivalent with the which occurs farther to the northwest. The Fort Hays Limestone Member consists of approximately 15 feet of light-gray, thick-bedded micrite containing locally abundant remains of the inoceramid clam ( sp.) and the small (Pseudoperna congesta). The Smoky Hill Shale Member consists of approximately 335 feet of fissile highly calcareous shale with about 15 feet of yellowish-brown micrite at the top. Strata near the middle of the unit contain abundant Pseudoperna congesta (Braddock et al., 1988a, 1988b). The Niobrara Formation is widely distributed and was deposited mostly in nearshore marine settings during the second late Cretaceous transgressive-regressive cycle.

NISP EIS – Paleontological Resources 19 Most fossil vertebrates collected from the Niobrara Formation were discovered in the Smoky Hill Shale Member in , although other geographic areas have produced less abundant and less well-preserved vertebrate remains. Among the most well-known Niobrara Formation fossils from Kansas are articulated skeletons of , fishes (including rare sharks), birds, and numerous plesiosaurs, , and turtles. Free swimming crinoids (sea lilies) have also been reported (Cobban, 1995). Mosasaurs, plesiosaurs, and fishes have been discovered within the Smoky Hill Shale Member of the Niobrara Formation in Larimer County, Colorado (Anthony and Smith, 1992; Martz, 1996). Fossil marine mollusks, cephalopods, and foraminifers are also locally abundant within the Niobrara Formation throughout its distribution. Niobrara Formation fossils have been the subject of numerous paleontological studies (Anthony and Smith, 1992; Cobban, 1995; Feager and Smidt, 1992; Martz, 1996; Russell, 1993; and many others). The Niobrara Formation was classified as Class 3 for this analysis and its distribution within the survey corridor is shown in Figures 2 and 3 (Kn, Kns, Knf).

NISP EIS – Paleontological Resources 20 8.0 EXISTING CONDITIONS

This section of the report presents the results of the record searches for previously recorded fossil localities within the APE for the NISP U.S. 287 western and northern alignment alternatives, and the field survey which was conducted within the APE for the NISP U.S. 287 western alignment (CDOT’s preferred alternative).

8.1 Museum Record Searches

At least four previously recorded fossil localities occur within or near the APE (Table 3). However, none of these are located within the western alignment. In addition to the four localities, an approximate 60% complete specimen of the fossil fish Xiphactinus from the Niobrara Formation at the cement quarry located at the southern end of the realignment alternatives along the existing Highway 287 right-of-way was reported to exist by a commenter on the NISP Draft Environmental Impact Statement (DEIS) (Warnock, 2008). This specimen was reportedly on display at the Fort Collins Museum of Discovery (Warnock, 2008). However, as of August 21, 2014, the specimen was not among the six fish fossils the museum had in its collections (personal communication with the Fort Collins Museum of Discovery, 2014), its whereabouts were unknown, and the locality of this specimen could not be confirmed; therefore, this specimen is not discussed further in this report. In addition to the localities discussed below, numerous other fossil localities have been recorded in the same geologic units elsewhere in Colorado and in adjacent states. It should be noted that fossil locality coordinates and locality maps are not provided because they are considered sensitive data and exempted from the Freedom of Information Act.

UCM L. 86050 is a roadcut in the Morrison Formation north of Ted’s Place along U.S. 287, and has produced a theropod tooth (UCM 80786 – cast of specimen) and six allosaur vertebrae which are now on display at the Friends of Visitors Center in Morrison, Colorado (Steve Wallace personal; communication, 2009). It is also the type locality for the freshwater sponge discussed in Section 7.1.3 which was described by Dunagan (1999). This locality and any remaining fossils there may be inundated with reservoir waters resulting from the NISP.

UCM L. 87092 is located at the south end of the Ideal Cement Quarries just to the west of the western alternative in the Smoky Hill Shale Member of the Niobrara Formation. This locality produced 35 sharks teeth identified as those of the crow shark (Squalicorax cf. falcatus), the mako shark ( mantelli), the goblin shark (Scapanorynchus sp.), and the mackerel shark (Cretolamna appendiculata). The locality was discovered during paleontological monitoring of the 1986-1987 realignment of U.S. 287 in the Laporte area (Indeck and Wallace, 1988; Unpublished paleontological data, UCM).

UCM L. 88015 is also west of the western alternative in the South Platte Formation of the Dakota Group along U.S. 287 in the Laporte bypass section. Twelve specimens of inoceramid clams (10 of which were identified as Inocermaus bellvuensis) were collected from this locality (Unpublished paleontological data, UCM). As discussed in Section 7.1.4, Waage (1955) reported plesiosaur vertebrae in the Dakota Group northeast of Laporte and north of the study area. The present disposition of these fossils is unknown.

NISP EIS – Paleontological Resources 21

Table 3. Previously Recorded Fossil Localities from within and Nearby the NISP Study Area. UCM, University of Colorado Museum of Natural History.

Locality#1 Institution Locality Name Formation Age Fossils 86050 UCM N of Fort Morrison Late Jurassic Dinosaur bones (theropod Collins tooth and vertebrae) and freshwater 87092 UCM Ideal Shark Niobrara Formation – Late Sharks teeth Smoky Hill Shale Cretaceous Member 88015 UCM Jeff’s No Dakota Group Early Inoceramid clams Excitement Cretaceous Clam Locality none Waage, n/a Dakota Group Early Plesiosaur Vertebrae 1955 Cretaceous 1It should be noted that fossil locality coordinates are not provided because they are considered sensitive data and are exempted from the Freedom of Information Act.

8.2 Field Survey

The southernmost approximate five miles of the western alternative is underlain by rocks of the Smoky Hill Shale and Fort Hays limestone members of the Niobrara Formation. This area has been strip-mined and reclaimed by the Holcim cement mine. Thus, most of the surface rocks and contained fossils in this area have been removed from their original stratigraphic context. However, some in situ strata remain, and fossils were present on exposed rocks throughout the area. The northernmost two miles of the western alternative bends to the northwest and crosses rocks of the Benton Group, Dakota Group (which forms a double ridge), Morrison Formation, Jelm and Sundance formations, and Lykins Formation before rejoining the existing U.S. 287 alignment.

Three fossil localities were recorded during the field survey of the western alternative for this study (Table 4). No fossils were collected because it is anticipated that better-preserved specimens could be obtained from excavations associated with highway construction when fresh rock exposures will be widespread and readily accessible within the study area. Observed fossils occurred mostly on weathered rock exposures and include: shells and molds of unidentified inoceramid clams (cf. Inoceramus sp.) in the Shale Member of the Niobrara Formation; plants including stem impressions, a partial palm frond, and other unidentifiable fragments in the Lytle Formation; and inoceramid clam shells and molds, a weathered mold of a partial baculite, and unidentified invertebrate burrows in the South Platte Formation.

Inoceramids (bivalve family Inoceramidae) are paleontologically important fossils that have been widely used in Mesozoic biostratigraphy. They evolved during the Permian and became extinct at the end of the Mesozoic. They were dominant elements of many level-bottom marine communities, and they achieved global dispersion during the Jurassic and Cretaceous, especially during intervals of restricted benthic oxygen and black-shale deposition (Harries et al., 1992). The majority of inoceramid species had intercontinental or cosmopolitan distribution, mirroring the widespread nature of their preferred habitats, their broad adaptive ranges, and probably long- lived larvae. Despite their broad distribution, inoceramids appear to have evolved very rapidly,

NISP EIS – Paleontological Resources 22 with species ranges commonly averaging 0.2-0.5 Ma. This greatly increases their utility in biostratigraphic studies, and stands in contrast to the “normal” slower evolutionary rates of bivalves in general, and to the evolutionary hypothesis that cosmopolitan taxa should have slow evolutionary rates because of the wide dispersion of their component populations (Harries et al., 1992; Kauffman and Harries, 1992).

Baculites (family Baculitidae), including the Genus Baculites, are extinct marine mollusks of the class Cephalopoda which includes the modern chambered nautilus, , and octopus, among others. Baculites are a type of heteromorph ammonite that had nearly straight shells, and achieved cosmopolitan distribution during the late Cretaceous. Their shells grew up to two meters in length, and because there is no counterweight to the head at the shell’s apex, they are believed by paleontologists to have lived in a vertical position with the head hanging down. As juveniles, the shells of baculites grew in a coil shape, but then straightened as the animals matured. Isotopic studies of baculite shells suggest that these pelagic animals inhabited the middle part of the water column. Like the shells of other ammonites, baculite shells consisted of a series of camerae (chambers) that contained gas which kept the buoyant. These chambers were connected together by a tube called a siphuncle, which connected with the head of the animal. The animal itself lived in the last chamber. Baculites could regulate the gas levels in each chamber in order to control their buoyancy as the chambered nautilus does today. The walls separating these chambers are called septa. Like other ammonites, baculites had intricate suture patterns formed at the juncture between the septae and the shell. The suture patterns are used by paleontologists to identify different species and are also highly useful for ammonite biostratigraphy.

Table 4. Fossil Localities Discovered within the Field Survey for the Western Alternative of the NISP U.S. 287 Realignment. Fossil locality coordinates are provided in the confidential appendix.

Field Locality# Lithology Formation Fossils DD012306-01 Interbedded bluish-gray shale Niobrara – Smoky Hills Inoceramid clam (cf. and limestone which weathers Shale Inoceramus sp.) shells and to orange-tan molds on exposed rock face DD041606-01 Blocky tan sandstone Lytle Formation – Dakota Wood and plant impressions Group (stems, palm fronds) on boulder DD041606-02 Interbedded dark gray fine- Middle shale member, Inoceramid clam shells, baculite grained sandstone and shale South Platte Formation – shell, trace fossils (indeterminate Dakota Group burrows)

NISP EIS – Paleontological Resources 23 9.0 RECOMMENDATIONS

1) At the time of this analysis, detailed information regarding the depth and extent of excavations required for the realignment of U.S. 287 for the preferred western alternative was unavailable. However, based on the project description, it is anticipated that large amounts of bedrock disturbance (estimated to be up to 200 feet deep and up to 500 feet wide in places) will occur during construction of the western alternative, especially in the vicinity of the . In combination with the known paleontological sensitivities of the geologic units within the study area and the presence of known localities within and near the project APE which have produced scientifically significant fossils, adverse impacts on significant paleontological resources are anticipated to occur during highway construction due to breakage and crushing of fossil remains. Potential adverse impacts on paleontological resources within the study area can be reduced to below the level of significance with paleontological mitigation, including construction monitoring. Construction monitoring of highway excavations in all Class 3 (Undivided Jelm and Sundance Formation, Dakota Group, Benton Group, and Niobrara Formation) and Class 5 (Morrison Formation) geologic units is recommended. Even though the Niobrara Formation within the western alternative corridor has been largely disturbed by mining activities, it is expected, based on the results of the field survey, that excavation of in situ rocks and contained fossils will also occur. The Lykins Formation is unlikely to produce any fossil remains, so monitoring of this unit is not recommended. Prior to construction, it is recommended that the CDOT staff paleontologist examine the final design plans and determine the extent of bedrock impact and the scope of paleontological monitoring required. Implementation of the mitigation measures detailed in Section 11.0 is recommended.

2) In general, the NISP area is paleontologically important due to its fossil-bearing rocks, most of which are known to contain scientifically important fossils. In addition to this study, which focused only on the realignment of U.S. 287, potential adverse impacts on nonrenewable paleontological resources elsewhere within the NISP footprint should be evaluated. UCM L. 86050, a Morrison Formation fossil locality which has produced dinosaur bones and a tooth within the existing U.S. 287 right-of-way, should be reinspected prior to its abandonment due to filling of the proposed reservoir. All significant fossils that have eroded onto the surface since the locality was last inspected should be properly collected, recorded, and transferred to an approved paleontological repository for permanent storage.

3) If any subsurface bones or other potential fossils are found anywhere within the greater NISP project area during construction, a qualified and permitted paleontologist knowledgeable of the rock units and fossils in the area should be notified immediately to assess their significance and make further recommendations.

4) As a general rule, if five or more years have elapsed since a paleontological survey has been completed, the field survey should be repeated in order to document additional fossils which may have weathered onto the surface.

NISP EIS – Paleontological Resources 24 10.0 IMPACTS ANALYSIS

The loss of any identifiable fossil that could yield information important to , or that embodies the distinctive characteristics of a type of , environment, period of time, or geographic region, would be a significant adverse environmental impact. Direct impacts on paleontological resources primarily concern the potential destruction of paleontological resources and the loss of information associated with these resources. This includes the unlawful collection of fossil remains by construction personnel. If potentially fossiliferous bedrock or surficial sediments are disturbed, project excavations may result in the destruction of paleontological resources and the subsequent loss of information (adverse impact). However, construction impacts also result in the exposure of fossils that may never have been unearthed by natural means. If mitigation measures are implemented, these newly exposed fossils become available for salvage, data recovery, scientific analysis, and preservation into perpetuity at a public museum (beneficial impact). Direct adverse impacts can typically be mitigated to below a level of significance through the implementation of a paleontological monitoring and mitigation program (see Section 11.0).

In general, for projects containing paleontologically sensitive geologic units such as the Morrison Formation, the greater the degree of construction-related ground disturbance, the higher the potential for adverse impacts on paleontological resources. For project sites that contain geologic units with no paleontological sensitivity, there is no potential for adverse impacts on paleontological resources. Potential adverse impacts on paleontological resources include direct (construction-related) impacts, indirect (operations-related) impacts, and cumulative impacts created by the potential long-term loss of the resources to society. These impacts are discussed below.

10.1 Direct Impacts

The potential for direct adverse impacts on scientifically significant subsurface fossils in fossiliferous sedimentary deposits known to contain them is controlled by two factors. These include: 1) the depth and lateral extent of the disturbance of fossiliferous bedrock and/or surficial sediments; and 2) the depth and lateral extent of the occurrence of fossiliferous bedrock and/or surficial sediments beneath the surface. Where the depth of disturbance exceeds the depth of occurrence, potential direct adverse impacts may occur due to breakage and crushing of fossils during ground disturbance associated with construction.

At the time of this analysis, detailed information regarding the depth and extent of excavations required for the realignment of U.S. 287 for the preferred western alternative was unavailable. However, due to the topography of the area, it is expected that large amounts of rock will need to be excavated for highway construction, particularly in the vicinity of the Dakota hogback.

Within the APE for the NISP U.S. 287 preferred western alternative, potential direct adverse impacts on paleontological resources are most likely to occur where bedrock strata of Class 3 and Class 5 geologic units are disturbed by construction (see Table 2). Construction excavations have the potential to adversely impact an unknown quantity of fossils which may occur on or below the surface in areas containing paleontologically sensitive geologic units. Without mitigation, these fossils, as well as the paleontological data they could provide if properly

NISP EIS – Paleontological Resources 25 salvaged and documented, could be adversely impacted (destroyed), rendering them permanently unavailable for future scientific investigation.

10.2 Indirect Impacts

Indirect impacts are those resulting from the post-construction normal operations of transportation infrastructure within the APE for the NISP U.S. 287 preferred western alternative. No indirect impacts on paleontological resources would be expected to occur from the continuing operation of the highway realignment or any associated facilities.

10.3 Cumulative Impacts

Cumulative impacts are effects on the environment which result from the incremental impact of the action when added to other past, present, and reasonably foreseeable future actions on the cumulative impacts area. They can result from individually minor, but collectively significant, actions taken over a period of time. Cumulative impacts on paleontological resources are difficult to evaluate and quantify because paleontological resources include both known fossil localities and resources whose precise locations are unknown because they are preserved beneath the ground surface in bedrock and surficial deposits.

The incremental loss of paleontological resources over a period of time as a result of project- related ground disturbance in the cumulative impacts area has the potential to result in significant cumulative impacts because it could result in the destruction of non-renewable paleontological resources and irretrievable loss of scientific information. However, when paleontological monitoring and impact mitigation is implemented prior to and during project construction, fossils are protected and information is gained. With the implementation of monitoring and mitigation, the cumulative impacts to paleontological resources resulting from project construction would be negligible. Further, any scientifically significant fossils discovered prior to or during ground disturbances related to project construction would benefit the scientific community through an increase in knowledge associated with the fossils.

NISP EIS – Paleontological Resources 26 11.0 MITIGATION MEASURES

As a nonrenewable resource, paleontological resources are unique. At the time fossils are discovered, many have already been subjected to a variety of destructive processes, including predation, scavenging, disarticulation, transport, primary weathering, diagenesis, erosion, secondary weathering, and damage through ground disturbance. Unlike other resources, it is difficult to develop measurable performance standards for paleontological mitigation because 1) fossils have been damaged by natural processes prior to their discovery, 2) fossils are often further damaged by construction activities that reveal their presence to paleontological monitors, and 3) there is no way to quantify how many fossils exist at the project site but were not exposed during construction. Therefore, the absence of fossils would not indicate failure of the mitigation measures. Paleontological mitigation seeks to salvage as many significant fossils as possible prior to their destruction during human-caused ground disturbance. Measurable performance standards in paleontology apply to monitoring and mitigation procedures, which ensure that fossil sites are documented thoroughly and accurately, and that fossils are collected according to professional paleontological standards.

The following are measures relative to a Tier 1 level of detail. They follow the guidelines of the Society of Vertebrate Paleontology (1995, 1996), and meet the standards of federal agencies and the State of Colorado. They have been developed to reduce adverse impacts of project construction on paleontological resources to a less than significant level. These mitigation measures have been used for ground-disturbing construction projects throughout the western , and have been demonstrated to be successful in protecting paleontological resources while allowing timely completion of construction. They should be implemented if, following inspection of the construction design plans, the CDOT staff paleontologist confirms that potentially fossiliferous strata within the APE for the NISP U.S. 287 preferred western alternative will be significantly disturbed. As stated in Section 9.0, monitoring is recommended in strata of the undivided Jelm and Sundance formations, Morrison Formation, Dakota Group, Benton Group, and Niobrara Formation.

11.1 Construction Monitoring

Before the construction permit is issued, a qualified and permitted paleontologist (project paleontologist) would be retained to produce a project-specific mitigation plan and who would be responsible for implementing the mitigation measures. This includes supervising the monitoring of construction excavations in areas with paleontological sensitivity.

The project paleontologist would attend preconstruction meetings to consult with the grading and excavation contractors. Language would be placed in the construction specifications to state that the paleontological monitor would be on-site during grading, excavation, or trenching operations. The construction contractor would be instructed via the written specifications and at the preconstruction meeting to stop construction if fossils, as verified by the paleontological consultant, were unearthed. Work would cease within the vicinity of the fossils so they could be recovered and removed from the site.

All project personnel would be required to attend a Worker Awareness Training Program prior to initiation of construction activities. The qualified paleontologist would administer the

NISP EIS – Paleontological Resources 27 paleontological resource portion of the training program. The program would educate construction personnel on the types of fossils that could be found in project excavations, their appearance, procedures to follow should they be found, and penalties for illegal collecting.

Paleontological monitoring would include inspection of exposed rock units and microscopic examination of matrix to determine if fossils are present. This work would take place during construction. Depending upon the types and significance of potential fossils, monitoring would be scheduled to take place continuously or to consist of spot checks of construction excavations. Paleontological monitors would follow earth-moving equipment and examine excavated sediments and excavation sidewalls for evidence of significant paleontological resources. The monitors would have authority to temporarily divert grading away from exposed fossils in order to professionally and efficiently recover the fossil specimens and collect associated data. All efforts to avoid delays to construction would be made.

If microfossils were present, the paleontological monitor would collect matrix for screen washing. In order to expedite removal of fossiliferous matrix, the monitor may request heavy machinery assistance to move large quantities of matrix out of the path of construction to designated stockpile areas. Testing of stockpiles would consist of screen-washing small samples (approximately 200 pounds) to determine if significant fossils were present. Productive tests would result in screen-washing of additional matrix from the stockpiles to a maximum of 6,000 pounds per locality to ensure recovery of a scientifically significant sample.

At each fossil locality, field data forms would be used to record the locality, measured stratigraphic sections, and appropriate scientific samples that were collected.

Paleontological monitors would be equipped with the necessary tools for the rapid removal of fossils and retrieval of associated data in order to prevent construction delays. This equipment includes handheld GPS receivers, digital cameras, cell phones, and laptop computers; as well as a tool kit containing specimen containers and matrix sampling bags, field labels, daily monitoring forms, field tools (e.g., awl, hammer, chisel, and shovel), and a plaster kit. Trucks would transport specimens and samples to an appropriate paleontological laboratory for processing.

In the event of discovery of unanticipated fossil remains, such as unexpected concentrations of fossils, unusually large specimens, or discoveries in sediments in which they were not expected, all ground disturbance in the area would cease immediately. The project paleontologist and appropriate project personnel would be notified immediately to assess the significance of the find and make further recommendations.

If any subsurface bones or other potential fossils are found by construction personnel during construction, work in the immediate area would cease immediately, and the project paleontologist would be contacted immediately to evaluate the significance of the find. Once salvage or other mitigation measures (including sampling) are complete, the paleontologist would notify the construction supervisor that paleontologic clearance has been granted.

The project paleontologist would have the authority to downgrade the monitoring effort if the paleontological potential of the project area is found to be less than anticipated.

NISP EIS – Paleontological Resources 28 In the laboratory, all fossils would be prepared, identified, analyzed, and inventoried. Specimen preparation and stabilization methods would be recorded for use by the designated curation facility.

A final paleontological monitoring report would include the results of the monitoring and mitigation program, an evaluation and analysis of the fossils collected (including an assessment of their significance, age, and geologic context), an itemized inventory of fossils collected including photographs where appropriate, an appendix of locality and specimen data with locality maps and photographs, an appendix of curation agreements and other appropriate communications, and a copy of the project-specific paleontological monitoring and mitigation plan.

All significant fossil specimens would be transferred to an appropriate curation facility such as a public museum. The fossils would be accompanied by the final paleontological mitigation report and all data in hard and electronic copy. The fossils would be curated and permanently housed in the curation facility where they would be available for study, education, and display.

NISP EIS – Paleontological Resources 29 12.0 REFERENCES

Anthony, D.J. and Smith, M.S., 1992, Palaeontology and stratigraphy of the Cretaceous Niobrara Formation, northern Front Range, Larimer County, Colorado: Geological Society of America Abstracts with Programs, v. 24, no. 7, p. 97.

Armstrong, H.J. and Kihm, A.J., 1980, Fossil vertebrates of the Grand Junction area: Grand River Institute, Grand Junction, Colorado, GRI/PRI Report no. 8050, prepared for the Bureau of Land Management, Grand Junction, Colorado, 201 p.

Armstrong, Harley J. and McReynolds, Elizabeth S., 1987, Paleontological significance of the dinosaur triangle, In: Paleontology and Geology of the Dinosaur Triangle (Averett, Walter R., Ed.), p. 55-63.

Bilbey, S.A., 1992, Stratigraphy and sedimentology of the Upper Jurassic – Lower Cretaceous rocks at the Cleveland-Lloyd Dinosaur Quarry with a comparison to the Dinosaur National Monument Quarry, Utah: University of Utah Doctoral Dissertation, 295 p.

Braddock, W.A., Connor, J.J., Swann, G.A., and D.D. Wohlford, 1988a, Geologic map of the Laporte Quadrangle, Larimer County, Colorado: U.S. Geological Survey Map GQ-1621, 1 sheet (scale 1:24,000).

Braddock, W.A., Wohlford, D.D., and Connor, J.J., 1988b, Geologic map of the Livermore Quadrangle, Larimer County, Colorado: U.S. Geological Survey Map GQ-1618, 1 sheet (scale 1:24,000).

Breithaupt, B.H., 1994, Wyoming’s Dinosaur Diversity: In: The Dinosaurs of Wyoming (Nelson, G.E., Ed.): Wyoming Geological Association 44th Annual Field Conference Guidebook, p. 101-104.

Bryant, B., McGrew, L., and Wobus, R.A., 1981, Geologic map of the Denver 1º X 2º Quadrangle, north-: U.S. Geological Survey Miscellaneous Investigations Map, I-1163, 2 sheets (scale 1:250,000).

Carpenter, K., 1979, Paleontological resources of Fort Carson, Colorado: Unpublished report prepared for Grand River Consultants, Inc., Grand Junction, Colorado, 68 p.

Chamberlain, C.K., 1976, Field Guide to trace fossils of the Cretaceous Dakota hogback along Alameda Avenue, west of Denver, Colorado: In: Studies in Colorado Field Geology (R.C. Epis and R.J. Weimer, eds.), Professional Contributions of the Colorado School of Mines, v. 8, p. 242-250.

Cobban, William A., 1995, Occurrences of the free-swimming Upper Cretaceous crinoids Uintacrinus and Marsupites in the Western Interior of the United States: U.S. Geological Survey Bulletin 2113-C, p. C1-C6.

NISP EIS – Paleontological Resources 30 Dodson, P., Behrensmeyer, A.K., Bakker, R.T., and McIntosh, J.S., 1980, Taphonomy and paleoecology of the dinosaur beds of the Jurassic Morrison Formation: Paleobiology, v. 6, no. 2, p. 208-232.

Drake, M. and Wahl, W., Jr., 1994, A description of two marine reptiles from the upper Sundance Formation, Wyoming: In: Nelson, G.E., ed., The Dinosaurs of Wyoming: Wyoming Geological Association 44th Annual Field Conference Guidebook, p. 179-187.

Dunagan, S. P., 1999, A North American freshwater sponge (Eospongilla morrisonensis new genus and species) from the Morrison Formation (Upper Jurassic), Colorado: Journal of Paleontology, v. 73, no. 3, pp. 389-393.

Elliott, D.K. and Nations, J.D., 1998, Bee burrows in the Late Cretaceous (late ) . northeastern Arizona: Ichnos, v. 5, no. 4, p.243-253.

Ellis, M.S., Gaskill, D.L., and Dunrud, C.R., 1987, Geologic map of the Paonia and Gunnison area, Delta and Gunnison counties, Colorado: U.S. Geological Survey Map C-109, 1 sheet (scale 1:100,000).

Feager, G.E. and Smidt, C.M., 1992, Cretaceous () fish in the Niobrara Formation of northern Colorado: Mesozoic of the Western Interior, SEPM Theme Meeting, 26 p.

Fort Collins Museum of Discovery, 2014, personal communication regarding a fossil fish from the Niobrara Formation reportedly in its collection.

Harries, P.J., Kauffman, E.G., and Crampton, J.S., 1992, Lower Euramerican Inoceramidae: A morphologic, taxonomic, and biostratigraphic overview: A report form the first workshop on early Turonian inoceramids, (5-6 Oct, 1992, Hamburg), 28 p.

Indeck, J. and Wallace, S.M., 1988, Results of paleontological monitoring of major new roadway excavation associated with project FC 287-3(30), Fort Collins Expressway – Laporte, northwest of Laporte, Larimer County, Colorado: Unpublished technical report prepared for the Colorado Department of Highways, 20 p.

Kauffman, E. G. and Harries, P. J., 1992, The ecology and life-habits of Cenomanian-Turonian Inoceramidae in North America: A report form the first workshop on early Turonian inoceramids, (5-6 Oct, 1992, Hamburg) [Abstract].

Lockley, M.G., 1987, Dinosaur Footprints from the Dakota Group of eastern Colorado: The Mountain Geologist, v. 24, no. 4, p. 107-122.

Lockley, M.G., 1990, A field guide to Dinosaur Ridge: Friends of Dinosaur Ridge, Morrison, Colorado, 29 p.

Lockley, M.G., 1992, Dinosaurs near Denver: Colorado School of Mines Quarterly, v. 92, no. 2, p. 47-58.

NISP EIS – Paleontological Resources 31 Lockley, M., Hunt, A., Holbrook, J., Matsukawa, M., and Meyer, C., 1992, The dinosaur freeway, a preliminary report on the Cretaceous megatracksite, Dakota Group, Rocky Mountain Front Range, and High Plains, Colorado, Oklahoma and : In: Field guidebook, Mesozoic of the Western Interior, SEPM 1992 theme meeting (Flores, Romeo M., Ed.): p. 39-54.

Martz, Jeffrey, 1996, First occurrence of (Reptilia, Mosasauridae) in Colorado: The Mountain Geologist, v. 33, no. 3, p. 65-70.

Mehl, M.G., 1931, A new bird record from the Dakota sandstone of Colorado: Geological Society of America Bulletin, v. 42, no. 1, p. 331.

Peterson, F., 1988, Stratigraphy and nomenclature of Middle and Upper Jurassic rocks, Western , Utah and Arizona: U.S. Geological Survey Bulletin 1633-B, p. 17-56.

Peterson, J.A., 1972, Jurassic System: In: Geologic Atlas of the Rocky Mountain Region (W.W. Mallory, Ed.): Rocky Mountain Association of Geologists, Denver, Colorado, p. 177-189.

Pipiringos, G.N., 1953, Correlation of marine Jurassic and related rocks in the Laramie Basin, Wyoming: Wyoming Geological Association Guidebook, 8th Annual Field Conference, p.34-39.

Rushforth, S.R., 1971, A flora from the Dakota Sandstone Formation (Cenomanian) near Westwater, Grand County, Utah: Brigham Young Univ. Biological Series, v. 14, 44 p.

Russell, D.A., 1993, Vertebraters in the Cretaceous Western Interior Sea: In: Evolution of the Western Interior Basin (Caldwell, W.G.E., and Kauffman, E.G., Eds.): Geological Association of Special Paper, vol. 39, p. 665-680.

Schaeffer, B. and Patterson, C., 1984, Jurassic fishes from the western United States, with comments on Jurassic fish distribution: American Museum Novitates, no. 2796, p. 1-86.

Snow, F.H., 1887, On the discovery of a fossil bird track in the Dakota sandstone: Transactions of the Kansas Acadamy of Science, v. 10, p. 3-6.

Society of Vertebrate Paleontology, 1995, Assessment and mitigation of adverse impacts to nonrenewable paleontologic resources – standard guidelines: Society of Vertebrate Paleontology News Bulletin, vol. 163, p. 22-27.

Society of Vertebrate Paleontology, 1996, Conditions of receivership for paleontologic salvage collections: Society of Vertebrate Paleontology News Bulletin, vol. 166, p. 31-32.

Steve Wallace, personnel communication regarding the disposition of the fossils from UCM locality 86050. Wallace was the CDOT staff paleontologist until 2013.

Tidwell, W.D., 1990, Preliminary report on the megafossil flora of the Upper Jurassic Morrison Formation: Hunteria, v. 2, no. 8, 12 p.

NISP EIS – Paleontological Resources 32 United States Forest Service, 1996, Probable fossil yield classification (PFYC): Developed by the Paleontology Center of Excellence and the Region 2 (USFS) Paleo Initiative.

Unpublished paleontological data, University of Colorado Museum, compiled 2003.

Waage, K. M., 1955, Dakota Group in Northern Front Range Foothills, Colorado: U. S. Geological Survey Professional Paper 274-B.

Waage, K.M. and Eicher, D.L., 1960, Dakota Group in northern Front Range area, in: Guide to the Geology of Colorado, Rocky Mountain Association of Geologists, p. 230-237.

Warnock, A. 2008. Comment letter on Northern Integrated Supply System Draft Environmental Impact Statement. Submitted to Chandler Peter, Denver Regulatory Office, U.S. Army Corps of Engineers. September 10.

Young. R.G., 1960, Dakota Group of the Colorado Plateau: Bulletin of the American Society of Petroleum Geologists, v. 44, no. 2, p. 156-194.

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CONFIDENTIAL APPENDIX

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