Solitude loop is an excellent mountain ride. It is a 6 mile loop with great views and great singletrack.
They have had a Tuesday night bike race there the past 6 weeks but if my info is correct it ended last night so we are taking back our Tuesday night at Solitude.
We will meet just outside of the lower parking lot at 6pm. They sometimes lock the gate early so just park on the side of the road.
http://www.utahmountainbiking.com/trails/solitude.htm