I wouldn't say there are tons of catfish here....I actually think its safe to say theres a better population of crappie and bass in Colorado than catfish. Given there are tons of places stocked with channels most don't have much size to them or the ones stocked don't surviveDo a forum search here on Clear Creek browns. Lots and lots of small brownies in that river. Fun for a half hour drive and nice scenery.
Welcome to Colorado, and you'll find the warm water fisheries are abundant, but not all that productive unless you're willing to put in the time and effort.
Lots of catfish in Colorado, if you care for that type of fishing. Trout are everywhere, they are BY FAR the most stocked fish in the state and you can find stocking reports online.
Crappie and bass are here, just not of the size and quantity you find elsewhere.
Put in the work and you'll find Colorado is a great fishing state.