WYDOT ENVIRONMENTAL ASSESSMENT June 2013 FHWA-WY-EA-13-01 Rupe Hill Landslide Along US 14 Crook County, Wyoming Wyoming Department of Transportation Project DR41319 Submitted pursuant to 42 U.S.C. 4332 (2) (c) Prepared For: U.S. Department of Transportation Federal Highway Administration & Wyoming Department of Transportation Prepared By: HDR Engineering, Inc. CONTENTS Page No. Chapter 1.0 Purpose and Need ............................................................................................... 1-1 The Proposed Action .............................................................................................................. 1-1 Location .............................................................................................................................. 1-1 Background......................................................................................................................... 1-1 Purpose of and Need for Action ............................................................................................. 1-7 Purpose .............................................................................................................................. 1-7 Need ................................................................................................................................... 1-7 Project Goals ........................................................................................................................ 1-11 Summary .............................................................................................................................. 1-11 Chapter 2.0 Alternatives .......................................................................................................... 2-1 Preliminary Alternatives .......................................................................................................... 2-1 Alternative 1—No Build Alternative ..................................................................................... 2-3 Alternative 2—Northern Realignment Alternative ............................................................... 2-3 Alternative 3—Landslide Remediation Alternative .............................................................. 2-4 Alternative 4—Southern Realignment Alternative .............................................................. 2-5 Refined Northern Alternatives ................................................................................................ 2-6 Alternative 2A ..................................................................................................................... 2-6 Alternative 2B ..................................................................................................................... 2-8 Alternative 2C ..................................................................................................................... 2-8 Alternative 2D ..................................................................................................................... 2-8 Alternative 2E ..................................................................................................................... 2-9 Alternative 2F...................................................................................................................... 2-9 Alternatives Carried Forward for Detailed Analysis ................................................................ 2-9 Chapter 3.0 Affected Environment and Environmental Impacts ......................................... 3-1 Land Use ................................................................................................................................ 3-1 Existing Conditions ............................................................................................................. 3-1 Environmental Effects and Mitigation Measures ................................................................. 3-4 Farmlands and Grazing Lands ............................................................................................... 3-4 Existing Conditions ............................................................................................................. 3-4 Environmental Effects and Mitigation Measures ................................................................. 3-5 Social Conditions and Community Resources ....................................................................... 3-6 Existing Conditions ............................................................................................................. 3-6 Environmental Effects and Mitigation Measures ................................................................. 3-9 Economic .............................................................................................................................. 3-10 Existing Conditions ........................................................................................................... 3-10 Environmental Effects and Mitigation Measures ............................................................... 3-12 Right-of-way Acquisitions ..................................................................................................... 3-14 Existing Conditions ........................................................................................................... 3-14 Table of Contents | TOC-i Environmental Effects and Mitigation Measures ............................................................... 3-14 Transportation ...................................................................................................................... 3-15 Existing Conditions ........................................................................................................... 3-15 Environmental Effects and Mitigation Measures ............................................................... 3-16 Soils and Geology ................................................................................................................ 3-17 Existing Conditions ........................................................................................................... 3-17 Environmental Effects and Mitigation Measures ............................................................... 3-19 Paleontology ......................................................................................................................... 3-21 Existing Conditions ........................................................................................................... 3-21 Environmental Effects and Mitigation Measures ............................................................... 3-22 Air Quality ............................................................................................................................. 3-22 Existing Conditions ........................................................................................................... 3-22 Environmental Effects and Mitigation Measures ............................................................... 3-23 Climate Change .................................................................................................................... 3-24 Existing Conditions ........................................................................................................... 3-24 Environmental Effects and Mitigation Measures ............................................................... 3-25 Traffic Noise ......................................................................................................................... 3-26 Existing Conditions ........................................................................................................... 3-26 Environmental Effects and Mitigation Measures ............................................................... 3-27 Water Resources and Quality .............................................................................................. 3-28 Existing Conditions ........................................................................................................... 3-28 Environmental Effects and Mitigation Measures ............................................................... 3-29 Wetlands and Aquatic Resources ........................................................................................ 3-32 Existing Conditions ........................................................................................................... 3-32 Environmental Effects and Mitigation Measures ............................................................... 3-32 Vegetation and Wildlife ......................................................................................................... 3-33 Existing Conditions ........................................................................................................... 3-33 Noxious and Invasive Weeds ........................................................................................... 3-35 Wildlife .............................................................................................................................. 3-36 Environmental Effects and Mitigation Measures ............................................................... 3-40 Threatened and Endangered Species .................................................................................. 3-44 Existing Conditions ........................................................................................................... 3-44 Environmental Effects and Mitigation Measures ............................................................... 3-46 Cultural Resources ..............................................................................................................