United States Department of Agriculture Supplement to the Soil Survey of Natural Clark County Area, Resources Conservation Service Idaho, Parts of Clark and Butte Counties National Cooperative Soil Survey This supplement is a publication of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local agencies. The Natural Resources Conservation Service (formerly the Soil Conservation Service) has leadership for the Federal part of the National Cooperative Soil Survey. The supplement was made cooperatively by the Natural Resources Conservation Service and the United States Department of the Interior, Bureau of Land Management; the University of Idaho, College of Agricultural and Life Sciences; and the Clark County Conservation District. It accompanies the most current official data for the soil survey of Clark County Area, Idaho, Parts of Clark and Butte Counties, available at http:// websoilsurvey.nrcs.usda.gov. Major fieldwork for the soil survey was completed in 2012. Unless otherwise indicated, statements in this publication refer to conditions in the survey area in 2018. The General Soil Map in this supplement may be copied without permission. Enlargement of the map, however, could cause misunderstanding of the detail of mapping. If enlarged, the map does not show the small areas of contrasting soils that could have been shown at a larger scale. Citation The correct citation for this supplement is as follows: United States Department of Agriculture, Natural Resources Conservation Service. 2019. Supplement to the soil survey of Clark County Area, Idaho, Parts of Clark and Butte Counties. http://soils.usda.gov/survey/printed_surveys/ Cover Caption Area southwest of Kilgore, Idaho. Idomonton, Longway, and Alex soils are on alluvial plains, and Parkalley and Latigo soils are on hills. The Centennial Mountains are in background. Nondiscrimination Statement In accordance with Federal civil rights law and U.S. Department of Agriculture (USDA) civil rights regulations and policies, the USDA, its Agencies, offices, and employees, and institutions participating in or administering USDA programs are prohibited from discriminating based on race, color, national origin, religion, sex, gender identity (including gender expression), sexual orientation, disability, age, marital status, family/parental status, income derived from a public assistance program, political beliefs, or reprisal or retaliation for prior civil rights activity, in any program or activity conducted or funded by USDA (not all bases apply to all programs). Remedies and complaint filing deadlines vary by program or incident. 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Submit your completed form or letter to i USDA by: (1) mail: U.S. Department of Agriculture, Office of theAssistant Secretary for Civil Rights, 1400 Independence Avenue, SW, Washington, D.C. 20250-9410; (2) fax: (202) 690-7442; or (3) email: [email protected]. USDA is an equal opportunity provider, employer, and lender. Additional information about the Nation’s natural resources is available online from the Natural Resources Conservation Service at http://www.nrcs.usda.gov. ii Contents Contents ...................................................................................................................... iii Preface...........................................................................................................................v Additional Resources ................................................................................................1 How This Survey Was Made .....................................................................................2 General Soil Map Units ...............................................................................................5 Soils That Formed on Lava Fields .............................................................................5 1. Malm-Coffee-Grassyridge .................................................................................5 2. Jacoby-Maremma-Blacknoll .............................................................................6 3. Vadnais-Chickenridge .......................................................................................6 Soils That Formed on Alluvial Plains ..........................................................................6 4. Fallert-Patelzick-Deadhorse .............................................................................7 5. Simeroi-Packmo-Whiteknob .............................................................................7 6. Idmonton-Longway-Alex ...................................................................................8 Soils That Formed on Hills .........................................................................................8 7. Shagel-Mogg-Peaspear .....................................................................................8 8. Parkalley-Latigo .................................................................................................9 9. Libeg-Owenspring-Philipsburg ...........................................................................9 Soils That Formed on Mountains .............................................................................10 10. Zeebar-Fritz-Ediebench ................................................................................10 11. Stringam-Sparky-Edgway ..............................................................................10 Formation of the Soils ...............................................................................................13 Geology ......................................................................................................................19 Rangeland Management ...........................................................................................23 Woodland Management and Productivity ...............................................................25 Wildlife Habitat ..........................................................................................................27 References .................................................................................................................31 Issued 2019 iii Preface This document is intended to provide supplemental information about the survey of the Clark County Area, Idaho, Parts of Clark and Butte Counties, that is not provided in the Web Soil Survey SSURGO data. This supplement and the online soil survey data provide information that affects land use planning in this survey area. They are intended for many different users. Farmers, ranchers, foresters, and agronomists can use the information to evaluate the potential of the soil and the management needed for maximum food and fiber production. The information can be used by planners, community officials, engineers, developers, builders, and home buyers to plan land use, select sites for construction, and identify special practices needed to ensure proper performance. It can also be used by conservationists, teachers, students, and specialists in recreation, wildlife management, waste disposal, and pollution control to help them understand, protect, and enhance the environment. v Supplement to the Soil Survey of Clark County Area, Idaho, Parts of Clark and Butte Counties This document was developed to supplement the soil survey of Clark County Area, Idaho, Parts of Clark and Butte Counties. The data and maps for the survey were published previously for the Soil Survey Geographic Database (SSURGO) and are available through the Web Soil Survey online application (http://websoilsurvey.nrcs. usda.gov). This document provides information not available in Web Soil Survey. It contains information about the physiography, geology, relief, and formation of the soils in the survey area and about the rangeland, woodland, and wildlife habitat in the area. With the completion of this soil survey, continuous soil mapping coverage of eastern Idaho is now available. This survey joins the soil surveys of Fremont County, Idaho, Western Part; Jefferson County, Idaho; Butte County Area, Idaho, Parts of Butte and Bingham Counties; Custer-Lemhi Area, Idaho, Parts of Blaine, Custer, and Lemhi Counties; and Targhee National Forest, Idaho and Wyoming. Location of Clark County Area, Idaho, Parts of Clark and Butte Counties. Additional Resources More information about soils is available from the website of the Soil and Plant Science Division of the Natural Resources Conservation Service (https://www.nrcs. usda.gov/wps/portal/nrcs/main/soils/survey/tools/). This site includes links to other sites where additional information specific to the soils in the survey area can be accessed, including the Web Soil Survey