Area 21, also referred to as Thunder Basin, is located in northeast Wyoming, southeast of the city of Gillette. Comprised mostly of open grasslands and some timbered hills, this unit contains a fair amount of public land.

This area is a general tag for residents and a Region B draw license for nonresidents. Using an outfitter will greatly increase your odds of success.

This unit has fair general access to the hunting public. Using an outfitter to access private lands will increase trophy potential and odds of success. There is extensive oil and gas activity as well as mining in the west part of the unit. Timbered hills in the northern and eastern part of the unit are a good place to start.

Public access in this unit is fair. There are a few County roads, BLM roads and secondary two-tracks. Getting permission to hunt private land in this unit is difficult without paying a trespass fee or the aid of an outfitter.

Grasslands dominate the unit, along with open sagebrush valleys and ponderosa pine studded hills in areas.

Gillette is the closest town of any size, and offers many options for lodging. Groceries, gas and other amenities can be found here as well. Camping is allowed on most public ground for up to 16 days in one location. You may camp in remote locations.