Fuel up on or near I-5, Marblemount is the last fuel going east until you get to Winthrop. there are 87 miles of no services between the two.
Up grades -- Newhalem is the start of the climb, first 10 miles are steep crooked and narrow, gear down, slow down. after crossing the lake it is another climb to Colonial creek ( nice camp) then it is up hill again to Panther creek. then it is pretty level until you start up Ruby creek. then the climb for 7-8 miles is steep, crooked. you'll be in a lower gear then it on again off again up hill until you crest Rainey pass, then a 2 mile down hill then up again into Washington pass at 5400 feet. then it is a 15 mile down hill into Mazama then it is a pretty drive thru the valley to Winthrop.
2000 Newmar mountain aire 4081 DP, ISC/350 Allison 6 speed, Wrangler JL toad.