"America's Most Beautiful Bike Ride". It goes around Lake Tahoe. Going around the lake itself is 72 miles. They add an extra out and back to Truckee to get you to a century if you want.

Also, in this area is the Tahoe Sierra Century. It goes from Squaw Valley up over Donner Summit and winds through Truckee. A TON of climbing. This ride is run by a friend of mine and the money goes to a great cause: music programs in our middle and high schools. http://www.tahoesierracentury.com/


Another challenging, but very pretty century is the Sierra Century in the Gold Country area. You wind through small towns and vineyards. I did it about 6 years ago. It was one of the best supported rides I've ever done. It looks like they've changed the route for this year, but I'd bet it's still a great ride.
http://www.sacwheelmen.org/sc2007/07home.html