The state park just published an official map on the trail closures at LOSRA. I don't expect any of the closed trails/roads to open anytime soon. You can download the map at:

http://www.parks.ca.gov/pages/712/files/Spillway_Inc_Closures_letter_land_20170218_1530_Spillway_DWR_CACDF114.pdf

The good news is that according to the map, the singletrack below the spillway is open (just stay off the Burma Road). Also the Potters and North Fork trails are open. (Getting over to the trails north of the dam is another issue.) Also, all the trails from the visitor center over to Loafer Creek are open.

May 4th, 2016:

We have just added a few new Mountain Bike rides to our MTB/Trail page and Calendar page.

LOBO has a club on Strava. Here is recent rides by the club members.