Occurrence

As of August 2020, CWD in free-ranging deer, elk and/or moose has been reported in at least 24 states in the continental United States, as well as two provinces in Canada. In addition, CWD has been reported in reindeer and/or moose in Norway, Finland and Sweden, and a small number of imported cases have been reported in South Korea. The disease has also been found in farmed deer and elk.

CWD was first identified in captive deer in a Colorado research facility in the late 1960s, and in wild deer in 1981. By the 1990s, it had been reported in surrounding areas in northern Colorado and southern Wyoming. Since 2000, the area known to be affected by CWD in free-ranging animals has increased to at least 24 states, including states in the Midwest, Southwest, and limited areas on the East Coast. It is possible that CWD may also occur in other states without strong animal surveillance systems, but that cases haven’t been detected yet. Once CWD is established in an area, the risk can remain for a long time in the environment. The affected areas are likely to continue to expand.

Nationwide, the overall occurrence of CWD in free-ranging deer and elk is relatively low. However, in several locations where the disease is established, infection rates may exceed 10 percent (1 in 10), and localized infection rates of more than 25 percent (1 in 4) have been reported. The infection rates among some captive deer can be much higher, with a rate of 79% (nearly 4 in 5) reported from at least one captive herd.

Chronic Wasting Disease Among Free-Ranging Cervids by County, United States, August 2020
Chronic Wasting Disease Among Free-Ranging Cervids by County, United States

As of August 2020, there were 315 counties in 24 states with reported CWD in free-ranging cervids. This map is based on the best-available information from multiple sources, including state wildlife agencies and the United States Geological Survey (USGS).

Arkansas
  1. Boone
  2. Benton
  3. Carroll
  4. Independence
  5. Johnson
  6. Madison
  7. Marion
  8. Newton
  9. Pope
  10. Searcy
  11. Sebastian
  12. Scott
  13. Washington
Colorado
  1. Adams
  2. Boulder
  3. Delta
  4. Douglas
  5. Eagle
  6. El Paso
  7. Garfield
  8. Grand
  9. Jackson
  10. Jefferson
  11. Larimer
  12. Kit Carson
  13. Logan
  14. Mesa
  15. Moffat
  16. Montrose
  17. Morgan
  18. Park
  19. Phillips
  20. Pueblo
  21. Rio Blanco
  22. Routt
  23. Sedgwick
  24. Summit
  25. Weld
  26. Yuma
  27. Washington
Illinois
  1. Boone
  2. Carroll
  3. Dekalb
  4. DuPage
  5. Grundy
  6. Jo Daviess
  7. Kane
  8. Kankakee
  9. Kendall
  10. Lake
  11. LaSalle
  12. Livingston
  13. McHenry
  14. Ogle
  15. Stephenson
  16. Will
  17. Winnebago
Iowa
  1. Allamakee
  2. Clayton
  3. Decatur
  4. Fayette
  5. Dubuque
  6. Wayne
  7. Winneshiek
  8. Woodbury
Kansas
  1. Cheyenne
  2. Decatur
  3. Edwards
  4. Ellis
  5. Finney
  6. Ford
  7. Graham
  8. Gray
  9. Grove
  10. Hamilton
  11. Haskell
  12. Hodgeman
  13. Jewell
  14. Kearny
  15. Lane
  16. Logan
  17. Meade
  18. Ness
  19. Norton
  20. Osborne
  21. Pawnee
  22. Pratt
  23. Phillips
  24. Rawlins
  25. Reno
  26. Rooks
  27. Rush
  28. Scott
  29. Sheridan
  30. Sherman
  31. Smith
  32. Stafford
  33. Thomas
  34. Trego
  35. Wallace
Maryland
  1. Allegany
Michigan
  1. Clinton
  2. Dickinson
  3. Eaton
  4. Gratiot
  5. Ingham
  6. Ionia
  7. Jackson
  8. Kent
  9. Montcalm
Minnesota
  1. Crow Wing
  2. Dakota
  3. Fillmore
  4. Houston
  5. Olmsted
  6. Winona
Mississipi
  1. Benton
  2. Issaquena
  3. Marshall
  4. Panola
  5. Pontotoc
  6. Tallahatchie
Missouri
  1. Adair
  2. Cedar
  3. Cole
  4. Crawford
  5. Franklin
  6. Jefferson
  7. Linn
  8. Macon
  9. Mercer
  10. Oregon
  11. Perry
  12. Polk
  13. St. Clair
  14. Ste. Genevieve
  15. Stone
  16. Taney
Montana
  1. Big Horn
  2. Blaine
  3. Carbon
  4. Daniels
  5. Gallatin
  6. Hill
  7. Liberty
  8. Lincoln
  9. Madison
  10. McCone
  11. Phillips
  12. Powder River
  13. Prairie
  14. Rosebud
  15. Sheridan
  16. Treasure
  17. Valley
  18. Yellowstone
Nebraska
  1. Arthur
  2. Banner
  3. Boone
  4. Box Butte
  5. Buffalo
  6. Cass
  7. Chase
  8. Cherry
  9. Cheyenne
  10. Custer
  11. Dawes
  12. Deuel
  13. Dundy
  14. Franklin
  15. Frontier
  16. Furnas
  17. Garden
  18. Grant
  19. Hall
  20. Harlan
  21. Hayes
  22. Hitchcock
  23. Holt
  24. Hooker
  25. Howard
  26. Keith
  27. Kimball
  28. Keya Paha
  29. Lincoln
  30. Lancaster
  31. Loup
  32. Morrill
  33. Nance
  34. Phelps
  35. Polk
  36. Red Willow
  37. Saline
  38. Scotts Bluff
  39. Sheridan
  40. Sioux
  41. Thayer
  42. Valley
  43. Webster
New Mexico
  1. Dona Ana
  2. Otero
  3. Socorro
New York
  1. Oneida
North Dakota
  1. Grant
  2. Divide
  3. McKenzie
  4. Sioux
  5. Williams
Pennsylvania
  1. Blair
  2. Bedford
  3. Cambria
  4. Clearfield
  5. Franklin
  6. Fulton
  7. Huntingdon
  8. Indiana
  9. Jefferson
  10. Juniata
  11. Perry
  12. Snyder
  13. Somerset
  14. Westmoreland
South Dakota
  1. Bennett
  2. Butte
  3. Corson
  4. Custer
  5. Fall River
  6. Haakon
  7. Harding
  8. Jackson
  9. Lawrence
  10. Meade
  11. Pennington
  12. Tripp
Tennessee
  1. Chester
  2. Fayette County
  3. Hardeman County
  4. Haywood
  5. Madison
  6. Shelby
  7. Tipton
Texas
  1. Dallam
  2. El Paso
  3. Hartley
  4. Hudspeth
  5. Medina
  6. Val Verde
Utah
  1. Carbon
  2. Daggett
  3. Grand
  4. San Juan
  5. Sanpete
  6. Uintah
  7. Utah
Virginia
  1. Clarke
  2. Culpepper
  3. Fauquier
  4. Frederick
  5. Shenandoah
West Virginia
  1. Berkeley
  2. Hampshire
  3. Hardy
  4. Mineral
  5. Morgan
Wisconsin
  1. Adams
  2. Crawford
  3. Columbia
  4. Dane
  5. Dodge
  6. Dunn
  7. Eau Claire
  8. Grant
  9. Green
  10. Iowa
  11. Jefferson
  12. Juneau
  13. Kenosha
  14. Lafayette
  15. Lincoln
  16. Marathon
  17. Marquette
  18. Milwaukee
  19. Oneida
  20. Portage
  21. Racine
  22. Richland
  23. Rock
  24. Sauk
  25. Sheboygan
  26. Vernon
  27. Walworth
  28. Washburn
  29. Waukesha
Wyoming
  1. Albany
  2. Big Horn
  3. Campbell
  4. Carbon
  5. Converse
  6. Crook
  7. Fremont
  8. Goshen
  9. Hot Springs
  10. Johnson
  11. Laramie
  12. Lincoln
  13. Natrona
  14. Niobrara
  15. Park
  16. Platte
  17. Sheridan
  18. Sublette
  19. Sweetwater
  20. Teton
  21. Washakie
  22. Weston