You may have a BLM office in your town. Maybe at least an office in the Federal building (P.O.).

The national office is:
U.S. GEOLOGICAL SURVEY
DENVER, CO 80225

The Wyoming state office is:
U.S. DEPARTMENT OF THE INTERIOR
BUREAU OF LAND MANAGEMENT
WYOMING STATE OFFICE
P.O. BOX 1828
CHEYENNE, WY 82003

There's also a company called DeLorme that make a decent atlas of topo maps of various states. That would be available at book store or even a sporting goods store.

One note on accessing public lands that a lot of people don't know, it is only legal to access public land via "publicly maintained roads". If a road sayd "PRIVATE" then it is not legal to traverse on it and even though it accesses public lands, would be illegal and tresspassing if you were to use it. Sucks, huh?

What area did you draw? And will you be hunting archery or rifle?