Michigan tackles both deer diseases simultaneously, mostly in separate regions. Bovine tuberculosis has been entrenched for decades within the northeast Lower Peninsula. Active chronic wasting disease surveillance covers the Upper Peninsula and some Lower Peninsula areas. The diseases' ranges remain largely separate.
KEY FINDINGS
- Bovine TB centers on an endemic core with a long history within the northeast Lower Peninsula, including Alcona, Alpena, Montmorency, Presque Isle and nearby counties. This is rare among wild U.S. whitetails; Michigan DNR says bovine TB historically has been very rare among wild deer.
- CWD monitoring follows a different geography. Focused sampling covers Upper Peninsula counties (Baraga, Chippewa, Dickinson, Houghton, Keweenaw, Luce, Mackinac, Ontonagon, Schoolcraft) along with some Lower Peninsula areas. Those locations are designated for surveillance. As of February 2026, 18 counties had confirmed CWD; 17 were within the Lower Peninsula, and Dickinson County was the sole Upper Peninsula county.
- Michigan operates two distinct containment approaches at the same time. Baiting regulations change between the state's peninsulas (Working Paper 12).
ITwo diseases, not one
The disease-management burden unique to Michigan
Deer-disease discussions mostly focus on CWD. Michigan, though, has dealt with bovine tuberculosis among wild deer starting in the mid-1990s. As of February 2026, CWD was confirmed across 18 counties, while TB surveillance continued. TB is caused by bacteria and also affects cattle; CWD results from prions and affects deer, elk and moose. The diseases occur mostly in separate regions of Michigan, although surveillance areas sometimes overlap, including Ogemaw County. The state must manage both across largely separate regions while working with the same population of hunters.
IIThe TB core
Northeast Lower Peninsula disease trouble lasting decades
In Michigan, bovine TB cases in deer center on counties within the northeast Lower Peninsula. The core includes Montmorency, Alpena, Oscoda and Alcona, and surrounding counties, including Presque Isle, have also recorded positive tests. First detected in 1994, the disease has remained in that cluster. Researchers and the DNR identify baiting and feeding as a major contributor to its establishment and persistence because those practices brought deer together. Since 1995, Michigan has conducted bovine TB testing in deer throughout the year. Every season, hunters in the northeast Lower Peninsula counties are asked to send in deer heads for tests. TB is a leading reason the affected counties face Michigan's restrictions on baiting and feeding. Evidence from that northeast Lower Peninsula core indicates that deer density and feeding locations drive disease transmission. The continuing problem has influenced Michigan's rules for baiting and feeding and its hunter sampling program since the mid-1990s.
IIIThe CWD front
More recent surveillance with its own geography
Michigan also faces CWD. As of February 2026, DNR confirmations covered 18 counties. Of those, 17 were within the Lower Peninsula, chiefly its central and southern areas; Dickinson County was the only one in the Upper Peninsula. Upper Peninsula counties named for focused collection are places being monitored, rather than the locations accounting for most detections. USGS describes CWD as a prion illness that has no treatment and takes a long time to incubate. With no cure available, managers rely on monitoring and regulations intended to slow its spread. These include baiting limits and restrictions on moving carcasses in locations where Michigan uses those rules. Hunters should keep in mind that CWD and TB chiefly occupy different Michigan areas, so a statewide rule seldom suits both.
Swipe table to see every column
| Disease | Core region | Representative counties (2025 focused collection) |
|---|---|---|
| Bovine TB | Northeast Lower Peninsula | Alcona, Alpena, Cheboygan, Montmorency, Oscoda, Otsego, Presque Isle, Roscommon |
| CWD | Mostly the central and southern Lower Peninsula (17 of 18 confirmed counties); Dickinson is the only Upper Peninsula county | Upper Peninsula surveillance areas: Baraga, Chippewa, Dickinson, Houghton, Keweenaw, Luce, Mackinac, Ontonagon, Schoolcraft |
Michigan uses different maps to manage deer diseases. Rules for baiting, testing and transporting carcasses depend on the area within the Upper Peninsula and Lower Peninsula.
IVWhy it matters
Two rulebooks for two maps
Understanding Michigan's regulations starts with its need to handle both diseases. A baiting ban in one area and permission in another, limits on transporting carcasses in some places but no such limits elsewhere, or required checks in particular counties reflect two containment problems affecting different locations. The peninsulas have different baiting regulations (Working Paper 12). Hunters have a straightforward rule to follow: look up the current requirements for baiting, testing and carcass transportation in the county they hunt.
NOTES AND SOURCES
- The Michigan DNR deer hunting preview for 2025 supplies the county lists for focused collection of bovine TB and CWD samples. michigan.gov/dnr.
- Limitations: the county lists are based on 2025 designations for focused collection and surveillance. Those designations change each year. This paper charts the geography of the diseases and how the programs are organized, without mapping prevalence rates.
Fully Drawn Research is an independent data analysis desk, not affiliated with any state wildlife agency, transportation agency, mapping provider or outfitter. Fully Drawn Research is independent and not affiliated with the Michigan DNR. This paper reports disease-surveillance geography and is not medical, food-safety, or wildlife-management advice; hunters should follow Michigan DNR and public-health guidance on TB and CWD testing and carcass handling. Current to 2025 Michigan DNR reporting.
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