What route do you plan to take on the Eastern return trip? I've done the OR to UT and OR to WY route many times and if you're keen on taking the scenic route I've got some suggestions for you.
Driving I-84 through the Columbia River Gorge is beautiful, heaps of waterfalls and hikes that sometimes take you up to the rim of the gorge. Also check out the Vista House which is 30 minutes out of downtown portland and on the Historic Columbia River Highway which was built in the 20's and modeled after European roads through the alps, but. that's explained at the Vista House.
After the gorge 84 isn't all that exciting except for a nice long hill climb just East of Pendleton and the distant Blue Mountains when you're passing through La Grande.
If you're willing to take the longer route you won't regret it. After the waterfall section of the gorge take the Hood River exit and get on Route 35 towards Government Camp. This road pulls you up into the mountains and wraps you 1/2 way around Mt Hood (a glacial capped volcano) and into a national forest. There are heaps of lakes up here, such as Trillium Lake, Clear Lake, Timothy Lake and Little Crater Lake which is really unique and beautiful. Lots of hikes up here to on old forest roads.
Take route 26 south past Madras until you get to Prineville and then continue to follow 26 East towards Ontario, OR where it meets back up with I-84. From there you can bee-line it to Mountain Home where you can get off and take Route 20 East through Hill City and Stanton Crossing. This will bring you up near the Sawtooth National Forrest and Sun Valley area where there are some hot springs.
Keep going on Route 20 until you come to Carey, ID. Route 20 and Route 26 merge as on from here through the Craters of the Moon National Monument and past Arco, ID. After Butte City, ID Route 26 will separate and head South from Route 20, but you should stay on Route 20 continuing through Idaho Falls and Rexburg until you get to Sugar City, ID. From here you'll turn onto state Route 33 which will bring you up to the backdoor of Wyoming and into the Teton Range. The road goes up over Teton Pass becomes WY state Route 22 and puts you right into Wilson and Jackson, WY and on the Snake River.
Anytime I drive these routes I make sure to put my fly fishing rod in the car because you can basically fish anywhere along this entire route I described to you and be in world class Trout waters, not to mention steelhead. If you have the time and the patience, it's worth every second of every mile.
