Heading SW on highway 285 go through the small town of Fairplay, CO. Just past highway 9 you'll find county road 18 turn right. For about 8 miles enjoy some scenery as you stare so of the most beautiful country Colorado has to offer.
You'll travel on a gravel road until you see the signs for Horseshoe on your left. Horseshoe offers 19, fairly secluded, campgrounds with firepits and picnic tables. As of this writing the cost was $12/night for a spot. Reservations are highly recommended. If you're an avid ATV'er campsite #19 backs to a hiking & ATV trail. If you're not into ATV's, try to steer clear of #19 b/c you'll have ATV's buzzing by your camp most of the day.
About 1 mile up the road is Fourmile Campground offering 14 more campspots.
The Horseshoe/Fourmile campsite provides a great weekend getaway. It took us about 2 hours from N. Denver with our camper and our kids.