There is a lot of public land for hunting and fishing in Colorado. Look at a map and look at all the National Forest lands thereon. Some of the areas may forbid hunting, but many areas allow hunting. The whole Weminuche Wilderness area is open to hunting in SW Colorado and perhaps the whole of the San Juan National Forest which contains the Weminuche Wilderness. I don't know about Utah, but grab your map and look for national forest lands. You might call some of the National Forest field offices to ask if hunting and fishing are allowed on these lands (usually fishing is, but hunting may not be such a sure bet).