Wood Strawberry doesn't stand out particularly from other small white flowers (though after closer inspection, you might conclude that it's the only flower sprouting tiny lemon sorbet popsicles). If you're familiar with the domestic strawberry plant, though, you'll recognize the leaves immediately.
Wood Strawberry is common in Yosemite - you can see lots of it in the Wawona Meadow area, for starters - but in my experience it's unusual to find it with ripe fruit. Too many woodland creatures are fond of it, and they get up before we do. With or without fruit, look for it in shady, moist areas, particularly around stream banks and meadow fringes.
Blooms: March - June
Fragaria vesca etymology: Fragaria derives from fraga, the Latin word for strawberry. Vesca is a form of the Latin word vescus, meaning small, thin, weak, or nibbled off, and appears in turn to derive from vescor, a Latin word meaning to eat or feed on. 
This Photo: Along the Wawona Meadow trail, early June