Overview:
This is a great springtime hike to the "Little Yosemite" section of Sunol Regional Wilderness, so named because its rock formations and rushing waters are a little bit like Yosemite.
A challenging option after checking out Little Yosemite is to take a left turn at the "W" tree (you can't miss it) and take on the rocks scramble up into a narrow canyon. Don't attempt in summer or fall: you could bump into a rattlesnake sunning itself on the rocks. Winter and early spring, while the vipers are still hibernating, is safer.
This route takes an early exit from the scramble, which could keep you clambering for hours otherwise.
Fees: $5/seasonal, weekends and holidays. $2 per dog (service dogs free).
Driving directions: From Interstate 680, take the Sunol/Calaveras Road exit and take Calaveras Road (a right turn for north-bounders, a left for south-bounders) for a little more than four miles and turn left at Geary Road.