Spicer Reservoir is about 8 miles long, and half of the reservoir is in the Carson-Iceberg Wilderness Area. Power boats are allowed on the west end (non-Wilderness), but have a 5 mph speed limit, so generally aren't a problem.
This reservoir has a rugged, rocky shoreline and great views. Nesting osprey can be seen in the summer. Fishing is allowed (with license, or course).
The reservoir is actually called "New" Spicer Reservoir, so presumably there was an old one here before. And based on the number of submerged trees, the old reservoir was at least 40 feet lower in depth than the new. Definitely makes for an interesting experience to paddle through a forest of dead/half submerged trees.
The winds can get rather strong, so be prepared. And the reservoir is at over 6000' in altitude.
If you want to add another day or two of paddling, you can also check out Union Reservoir and Utica Reservoir, which are close neighbors to Spicer. They are accessed by a dirt road off of Spicer Reservoir Road.
Pit toilets at launch ramp. Official campsites available near the launch ramp.
No fee for parking (including overnight) nor to launch.
There is a fee to camp in an official campsite, but it is free to camp elsewhere. Wilderness permit required if you camp overnight at the east end of the reservoir.
From the Central Valley, take Highway 4 towards Bear Valley. About 3 miles before you get to Bear Valley, there will be an intersection for Spicer Reservoir Road (watch for the Sno-Park signs - there is a Sno-Park at the intersection). make a right and drive 10 miles or so until you get to the launch ramp.
US Forest Service
There is a map at http://www.fs.fed.us/r5/stanislaus/visitor/spicer.shtml