If you decide on the Sierra Cascade route, I do not recommend riding the central valley up the 49, even though it's not the desert, it's plenty hot, also I believe most people tour up the 120 through Yosemite. The problem is ( I have done it before) it is at least 70 miles (all climbing) to get to Tualommee (Rats- I forget how to spell it) Meadows. you could stay on the 49 to the 20 which takes you to Truckee, (not so bad) and then continue north. What you are trying to do is the: " Escape The Arizona Heat Tour" If you were to post on the Crazy Guy website. Yuk Yuk Yuk. Good Luck.