Start in the large public parking area just south of the Truckee River and follow the Truckee River Bike Path over a bridge and along the north side of the river. This part is easy, beautiful, and suitable for all abilities. It's crowded, so don't go too fast or get too distracted by the bikinis... I mean rafters. When you come to the River Run restaurant and Alpine Meadows, turn left and head towards the ski area.
Turn left on Snow Crest Road and climb uphill a while. Before descending, look for a dirt road going off to the left. This is 16N48, which you follow steeply uphill for a while. This first part is rocky, loose, and not very nice, but it's over quickly. It then gently climbs up through dense pine forest with glimpse views of the mountains and Lake Tahoe on much smoother, fast dirt.
After a few miles, you level off and are now in the Paige Meadow area, where there are tons of trails. Feel free to explore - they all reconnect eventually, and this area is the highlight of the ride. To follow this route, pass the first left turn option (which leads to Paige Meadows) and keep a sharp eye out for another left. It has a "no vehicles" sign but no name. Walk your bike across a short boggy section and you'll soon intersect the Tahoe Rim Trail - Truckee River to Ward Creek.
Turn left and enjoy the spectacular trail through the meadow. Once done, loop around a little more if you like, or if you're ready to return, follow the TRT down a steep singletrack back to the Truckee River, and your car soon after that.
Here are a couple of other ways to get to Paige Meadows from either 64 acres via Granlibakken Road or Ward Creek Road vs trying to ride up the gnarly steep, loose, rocky single track trail to the north side of Granlibakken.
From 64 acres the easiest way is to take the TCPUD bike path to Granlibakken Road to Rawhide Road and on up the fire road about 2 + eventually into Paige Meadows.
Another easy, but longer way is to ride up Ward Creek Road all the way to Chamonix to the end and enter through the green gate. Ride the double track north to the single track and head east into the meadows about 1 mile and to the right