Afaik, all the autocrosses in the region are in the Denver and Colorado Springs area- several WY folks make the trip to events

http://rmsolo.org/ covers both the Rocky Mountain and Continental Divide region events.  Come out and have fun with us!

From a social standpoint, there are several regular northern Colorado gatherings, which you'll find in the RMSOLO forums- a very friendly, active, helpful forum.

 Next event is a two day school and autox event at PPIR on June 26th/27th, you could make a weekend of it. 

This is a very delayed response, but yes, there are other autocrossers in southern Wyoming.

The Casper corvette club has events for corvette owners.

Those of us down here find the events held by Rocky Mountain Solo to be well worth the travel to
Denver or Colorado Springs.

RMS is hosting a Pro-Solo in two weeks (Jul 9/10), come on down!

Check out
http://www.rmsolo.org/forums/index.php