I don't how crazy you are but the best way to do it is go hiking in the mountains with an idea of whats going on. Colorado has a lot of incredible stuff. A lot of really incredible stuff. Look for shorl in Salida(theres a kayak competition there every summer too...good town) and theres lots of good colored beryl around South Park...
something easy and fun...theres a pegmatite up near the buffalo lookout at Gennessee about 30 minutes out of Denver. It's on the frontage road and theres some nice quartz and some little garnets in there. Bring a hammer:)