Wildernet: Colorado
- Find detailed information on hiking trails, campgrounds, and outdoor activities in the area.
- http://www.wildernet.com/pages/area.cfm?areaname=Colorado

Mountain Wayfarer
- Small boat sailing and kayaking in Colorado and the Southwest. Photo gallery, Wayfarer dinghy links, links to other Colorado sailing resources.
- http://users.frii.com/uliasz/wayfarer/

Adventure Specialists
- Colorado ranch based group of educated adventurers. Horse trips, treks, climbing, archaeology, research expeditions.
- http://www.adventurespecialists.org/

Café Laerbs
- Mountain biking, skiing and frisbee articles and pictures.
- http://www.coloradopowder.com/

Colorado Outdoor Recreation Guide
- A site for in-depth information on Colorado campgrounds, hiking, mountain biking, climbing, state parks, wilderness areas, national forests, and 4-wheeling.
- http://www.wildernet.com/colorado/index.html

Tenth Mountain Division Hut Association
- 24 huts styled after the European tradition and linked by over 300 miles of trails provide overnight shelter Details of huts, how to get there, backcountry travel hints, reservation info, user forums.
- http://www.huts.org/

Colorado Recreation Guide by Wildernet
- Comprehensive outdoor recreation guide for Colorado. Over 2000 pages of information on specific campgrounds and over 900 trails, organized into 250 geographic areas and into 30 activity types.
- http://www.wildernet.com/pages/colorado.cfm?areaname=Colorado

American Adventure Expeditions
- Offering whitewater rafting, kayaking, rock climbing, mountaineering, backpacking, mountain biking, and fly fishing.
- http://www.americanadventure.com/

Colorado Guide
- Comprehensive searchable database of trails, campgrounds, lakes, rivers; including information on rafting, skiing, fishing, four-wheeling, wilderness areas, and wildlife watching.
- http://www.coloradoguide.com/

Rocky Mountain Recreation
- Summer and winter activities in Colorado.
- http://www.rockymtnrec.com/

Hiking in Colorado
- Includes descriptions of more than two dozen hikes, a Hike Difficulty Calculator, and lots of photos.
- http://www.hikingincolorado.org/

Horizon Adventures, Inc.
- Colorado backcountry adventures for teens ages 13-17, accredited by the American Camping Association (ACA). Horizon Adventure Program.
- http://www.horizonadventures.com/