On your trip out from Colo--assuming north/south itinerary--take hwy 26 past mt Hood and Government Camp. Do NOT take I-84 through the Dalles. Although it seems like the easier/more reliable route it is just the opposite--frequently closed for weather or ice when the 26 is just fine.
Be sure to stop at Govy and mt Hood. You can get world-class huckleberry pie in Govy, and you can even hunt for huckleberries in the meadows surrounding town. Just be aware that in sept the black bears are gorging themselves on the same huckleberries and they do not appreciate interruptions. Government Camp is filthy with black bears; they raid the garbage in town at night and roam the huckleberry fields during the day. Try the pie instead!
Mt Hood is by far the most interesting mountain in oregon, but if you just don't want to go there, you coul go over santiam pass instead. This will take you through Bend and then Sisters, where there is a nice little cg and miles of free boondocking. Highly recommended!