The classic Honda picture(approximately 1981) of me and my XR185 was taken at about 11,000 feet on a high mountain trail from Ouray, Colorado, to Carson and Lake City Colorado. Yes i did "unstick" it!
Riding up this high has its challenges. Air is very thin even at the mere 5000 feet in Denver. Where we ride is twice that high. We last went in 2017. Breckinridge Colorado is 9600 feet. The condo where we based out from was over 10,000 feet. This last time I went, I felt the altitude more than any previous trip. Not so much when we rode, as it night it was very hard to sleep because you would keep waking up needing more oxygen!
When we first started going to Colorado, I had large two stroke Bultacos. Two strokes are not a good choice for high altitude. Even with rejetting, performance is only a portion of what it is at sea level. Then we started taking XR Hondas. First my 185, then an XR200. In later years we moved up to larger 4 strokes. A Kawasaki KLX300 was a decent mount! One year I had a KTM 450 EXC with a Rekluse clutch; it was the best--though eventually I sold it because it was too tall for an old guy to safely ride. Last trip was my Suzuki DRZ400 which was a fine choice, decent power and a great suspension. We also took an XL185 as a backup for a friend. It proved to still be a good choice. It could still climb anything,(not fast), and the suspension was ok.
My college roommate and I have been riding in Colorado and New Mexico more than 10 times over the years. I have included a montage of pictures. If you want off road fun and vistas that you can't get anywhere else, Colorado is the place to go