The Continental Divide Trail runs 8 miles from Monarch Pass to Boss Lake, passing through Monarch Mountain ski resort and past Hunt Lake along the way. This section of trail is rarely traveled, and especially little-used by mountain bikes, despite being bike-legal. Consequently the trail can be extremely narrow, faint, rocky, and exposed, making for very challenging riding and plenty of hike-a-bike. However, the absolute solitude (I rode on a Saturday and didn't see another soul) and the miles and miles of breathtaking views (you'll be above treeline for about 6 miles, topping out at 12,560 feet) more than make up for the slow speed riding!
Finally, be prepared for a ridiculously steep, tight, technical, and at points barely rideable descent off the top of the Crest. This isn't a ripping high speed descent like you'd get on the other side of the highway, but will instead challenge your technical skills in a totally different way.