This is a link to a compilation of KML/KMZ 4WD routes in Colorado. I have acquired most of this information from the Trail Damage website ( which is primarely for 4 wheel drive vehicles. The second is from IntrepidXJ's Adventure Weblog: Other sources used to create Google Earth Tracks are visual inspection of Google Earth KMZ file that includes 355 fire roads and trails in 36 of Colorado's Counties. The data obtained from the website Trail Damage is also available in GPX format, see below.

The Google Earth KMZ file includes 3 subfolders “Colorado Motorcycle & 4WD Roads”, “Scenic Paved Roads”, and Colorado Counties”. The Trails in the “Colorado Motorcycle & 4WD Roads” are segregated into the 36 Colorado counties. There are occasional overlaps with some of the roads and trails, but not too many. Unfortunately the “Scenic Paved Roads” is currently a little light, as it only contains the following 3 roads: “Peak to Peak Scenic Drive”, “Independence Pass Road”, and “Highway 285”. It may not be possible to convert the last three to GPX files as they were obtained from ESRI SHP files and probably contain too many points. The KML of the Colorado Counties was useful in compiling and segregating this information and may be useful to you.

The Excel Spreadsheet titled “Colorado Motorcycle Trails.xls” contains all of the roads and trails in the Google Earth KML file categorized alphabetically by Colorado County and alphabetically by Trail. It includes the rating system from the web site Trail Damage and up to eight nearby trails for each trail. This file could be easily modified by those Colorado ADVRIDER’S who are both experienced and interested in providing an actual difficulty rating as well recommended motorcycle size.

Lastly I have not ridden over most of the roads contained in this compiled data and as such cannot personally attest to the accuracy of the information. However, I would not have included the information if I did not have a degree of trust from the various information sources.

The link below is to an Excel Spreadsheet in a single web page(mht)format that lists all of the trails by County and includes the ratings from Trail Damage regarding the level of difficulty for a 4 Wheel drive vehicle not a motorcycle. If some experienced Colorado local were so inclined he could very easily download this to a spreadsheet, insert a couple of columns and provide motorcycle ratings for small, medium and large motorcycles. Just a subtle hint. My off road abilities and location prohibit me from attempting to rate these roads. Just click on the link and save to your computer and then double click and it will open into your web browser.
This link provides you access to many of the trails listed above in GPX format, most of which were obtained from Trail Damage.
Colorado 4WD Trails All County

A ride report I prepared for my 2010 Colorado vacation is shown at the link below.
This is a link to my Google Earth kmz from my 2010 Colorado Vacation and Ride Report.
Hartman Rocks Google Earth KMZ file
    This link includes many roads and trails south of Gunnison Colorado up to and including Los Pinos Pass, Cebola Creek Road and many others.