Why units exist
Units are the accounting unit for harvest. Biologists set quotas per unit from survey and harvest data, so season dates, weapon restrictions and draw odds all attach to that polygon rather than to the land itself.
Reading the map
HuntTrack draws Idaho GMUs live from the Fish & Game feature service. Boundaries follow roads, ridges and rivers — verify which side of a highway centreline you are on before shooting.
General versus controlled
Overlapping controlled hunt areas often sit inside a general unit with different dates and a draw requirement. Always confirm against the current season proclamation.