Ther are over 100 Over-The-Counter (OTC) Units to hunt Antelope in Colorado.
Units that don't hold a lot of Antelope:
40,60,60,63,64,65,71,72,73,74,75,76,77,78,711,741,771, and 751 (great Elk and Deer Units).
A great place for OTC Antelope is the Eastern Side of the state. Look at the unit map HERE.
There is a lot of State Land to hunt in Units; 93,97,98,119,123,125,126,128,129, and 135