R2 Road Conditions: tire chains or 4-wheel-drive with snow tires required on Hwy 41, and Big Oak Flat Road including Hwy 120 west of Crane Flat and the Hetch Hetchy road. R1 road conditions on Hwy 140 and all roads within Yosemite Valley. Road conditions can change at any time. For the most up to date road information please call 209-372-0200, press 1, then 1.