Can be snow-covered, December through March.
Beaver Creek is a motorcycle trail and has a number of berms, which have been burned in by motorcycles (watch out for bikes of all types).
The last part of the trail is very scenic with aspen groves and some great rock formations. There are a lot of great places to stop and take in the canyon views.
The trail can be loose in the fall and there are some deep water crossings in the spring, but that is part of the fun. That said, be prepared to get your feet a little wet.
There are lots of connecting trails around that can be used to make this run into a loop.