My route would be south on 101 and catch hwy 20 between Willits and Ukiah, Then Hwy 20 over to Williams and south on I 5 to Stockton, and then `East on Hwy 4, cross town freeway, over to Hwy 99. South on 99 to Merced and then Hwy 140 to Yosemite. Fuel up at safeway in Willits on 101 and then again at Merced before heading to Yosemite. (No fuel in Yosemite) Some will recommend hwy 120 in Manteca but that puts you over New Preist's grade which is kind of steep and windy. Doable but I don't like it my self in a MH. OK in a car.