Do you have anything more specific? Names, locations, etc?
Those were Locations... all those cities have numerous trails nearby, anything from easy dirt to crazy rock. And finding good back country camping spots is usually pretty easy.
I also agree that the guide to colorado backroads is an excellent book
TrailDamage.com is also a good source for finding trails in the area, and they do a good job of rating them and describing them.
Some of my personal favorite trails w/ camping are:
-Handcart Gulch - Near Bailey
-Lincoln Creek - Near Aspen
-Reno Divide - Near Crested Butte
-Tincup Pass - Near Buena Vista (St. Elmo)
-Medano Pass - Near the Great Sand Dunes (trail ends at the park's parking lot)
As someone else said, get the book by Charles Wells for Colorado. He actually has 2 separate books for the state. One for Northern and another one for the rest of the state. Both highly recommended.
And, definitely check out the Traildamage website. Very good descriptions on there with tons of pictures and even video.
I've only been here a year, so my experience of trails is a little on the low side, but we did Mt. Antero last year and that is awesome. Not real hard, but unbelievable views and switchbacks. You can check out my trail report here on this website.
Another trail I've heard is great is Chinaman Gulch near Buena Vista as well. I have not been on this trail....yet. But like the others said - the possibilities are endless here.
All over! There are tons of good trails in Colorado, and tons of 4Wheel groups too.
I personally love wheeling out near Buena Vista, Crested Butte, Aspen, and down near Ouray and Teluride!
I may live in the OK (for now) but since the year I was born we take almost 4 trips up to CO for a week to two at a time! Our whole family has a cabin outside of Buena Vista, and that whole area is just beautiful. A real fun day trip is up Tin Cup pass (by St. Elmo), takes you over the continental divide, trail is well wide enough for an H1. Lot of areas up towards Leadville as well.
"The only thing necessary for evil to triumph is for good men to do nothing." ~Edmund Burke~