The Two-Disease State: Mapping Michigan's Bovine TB and CWD

Most states manage one deer disease. Michigan manages two at once, in different corners of the state: bovine tuberculosis, entrenched for decades in the northeast Lower Peninsula, and chronic wasting disease, under active surveillance across the Upper Peninsula and parts of the Lower. Two diseases, two geographies, one herd. And a management problem no other state faces at this scale.

Chronic wasting disease dominates the national deer-health conversation, but Michigan's story is older and stranger: it is the one state that has fought endemic bovine tuberculosis in wild deer for decades and now runs CWD surveillance on top of it. The two diseases are biologically different (TB is a bacterial infection shared with cattle; CWD is a prion disease unique to deer), and they sit in different parts of the state. Managing either alone is hard. Managing both, on two maps, with one hunting public, is the distinctive Michigan challenge.

Bovine TB in Michigan deer is concentrated in a cluster of northeast Lower Peninsula counties (Alcona, Alpena, Montmorency, Presque Isle and their neighbors) where it has persisted since the 1990s, sustained in part by historical deer-feeding that concentrated animals nose to nose. The state runs focused TB collection there every season, and the disease is the original reason Michigan grew suspicious of baiting and feeding: a TB core is a standing demonstration that concentrating deer spreads disease. It is a contained but stubborn problem, and it has shaped Michigan deer policy for a generation.

CWD is Michigan's second front, and it sits mostly elsewhere: a run of Upper Peninsula counties under focused collection, plus detections in the Lower. Because CWD is a prion disease with no treatment and a long incubation, the tool is surveillance and containment rather than cure: test heavily, track the edge, and restrict the movement and concentration of deer where it appears. The important point for a hunter is that Michigan's CWD map and its TB map are largely different places, which is why a single statewide rule rarely fits both.

One state, two diseases, two maps. Michigan cannot write a single deer-health rule that fits both corners, so it doesn't.

The dual-disease reality is the key to reading Michigan regulation. When the state bans baiting in one place and allows it in another, restricts carcass movement here but not there, or runs mandatory checks in specific counties, it is not inconsistency. It is two containment problems being managed on their own geographies. The clearest expression of that logic is the baiting divide between the peninsulas, which follows directly from where the diseases are (Working Paper 12). For the hunter, the practical rule is simple: know which map you are hunting on, because Michigan has two.