I recently joined a Meet-up group that is dedicated to mountain biking, and while I have not gotten together with these people very much, I did a recently. We drove to a stretch of single track in Boulder County known as the Sourdough Trail.
This trail is an extremely strenuous ride. It starts at about 9200 feet of elevation and rises to about 10,200. It is not very well maintained, so as a consequence it is fairly badly eroded. So, this means lots of loose rubble on the trail. It is not super steep, but between the baby heads and the elevation, the rider is really breathing. When you stop and catch up with your breathing, when you start again, your legs feel strong, but your lungs quickly fail and the ride becomes instantly anaerobic.
Here is our small group that made the Meet-up. Justin is on the right, and Nick is in the middle. Both are great guys and good riders. Left me in the dust! This shot shows the upside of the Sourdough Trail, tho: it is through the woods. Lots of shade, and combined with the elevation, a good place to ride in the summer heat. One can also see a bit of brown in the trees, a result of beetle kill.
Here is an interesting feature. Nick says to me, "There's a few fun little spots ahead, it's probably best to speed up when you see them." This certainly piques my interest but gets me a little bit skeert. I have no idea why the trail builders/maintainers would do this, but it looks like that if a tree falls down over the trail, instead of cutting a portion of it away, they simply build ramps of dead logs to help one ride over it. Actually, it was fun.
Here is Justin coming down the trail. It was about 6 miles up and so one gets a hoot of a long descent for the ride back to the car. By the end, my hands were cramping from hanging on and applying the brakes.
Here was our reward at the top. Left Hand Reservoir. Late June, and still snow on the ground.