Just after turning off CA Hwy 4 to Bear Valley Mountain resort is a free parking on the right with trailheads going up the ridge. In winter it becomes a SNOpark when HWy 4 is closed and unploughed from Lake Alpine going east (winter parking permits for sale at Ski stores etc).
In summer the trail is easy to follow. If still snow-covered it becomes an unmarked adventure, best with crampons/snowshoes or ski on skins to climb straight north from the parking and east along the ridge above Poison canyon toward Mt Reba road. Great views of Mokolumne Wilderness to the north and Carson-Iceberg Wilderness to the south.
You can then hike (or ski) down into Poison Canyon which loops back toward the SNOpark for a great reward of a half-day backcountry outing, or continue along the ridge above Hwy 4 and loop back down a few miles further east for a longer tour. With snow you can also drop into some sweet powder bowls to the north and climb back out the way you came.