From Rhododendron to Govt. Camp it is about 5 miles at 6%. After that you have some shorter pulls of a few miles each maybe 4-5%. Dropping into Warm Springs is about 6% for five miles then about the same up the other side. Watch speed thru Warm Springs.
26 is a good trip. You will start the serious climb from Rhodendreon to Government Camp. Then there is a short down and then another climb past CJs gas station over the Bluebox pass. You will also have a long down hill and climb into and out of Warm Springs. Pulled this route hundreds of times pulling my 36 foot fiver. I actually like it much better than 20 out of Salem. 26 is a easy drive.