There is some backcountry spots in the West Magnolia area just south of Nederland. Lots of good hiking/mountain biking trails through there and great views of the continental divide. Also, the "Fourth of July" trailhead on the Peak to Peak Highway north of Nederland offers maintained camping spots in a great locale.
We have also camped farther down south just west of Momument. For that trip, we just followed dirt roads west until they petered out. Wonderful camping spot that I'll most likely never be able to find ever again!
There is some free camping just west of Salida south of Beuna Vista that offers a great location near several 14ers, biking, and fishing.
There's a ton more out there but those are the ones that jumped to mind. When are you heading out?
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