Your RAV4 will make the trip - no problem. Just take it easy on the steep dirt sections!
In spite of advice you may have read to the contrary, do not go down Silver Canyon road. Just fill up your RAV4 in Bishop or Big Pine, and you'll have plenty of fuel for the return trip.
Since 1992, the date of Fishmonger's trip, the Silver Canyon road has experienced cycles of flash-flooding and erosion, and may not be in the best of shape. I don't know the last time it was graded; the White Mountain staff use the regular road to commute to and from Barcroft Station. There are also a few stream crossings in the lower part of the canyon. It is extremely steep, and tough on gear-boxes and brakes. I've been up and down that road several times in the past in high-center 4X4's (on SAR missions) and mountain bikes. It's one to avoid, but that's just an old local's opinion...
