Mt Washburn is on the Eastern side of Yellowstone, between Canyon and Tower. Along the road there are two trails that go up it, one is the Dunraven pass trail and the other is the Chitteden Road, which is a dirt road. If I had known at the time about the Dunraven Pass Trail, I would have taken it, as apparently it is more scenic. However, I vouched to crawl up the Chitteden road instead.
The view from above is spectacular. A good three miles to the top (and of course, you have to go back) but definitely a hike worth doing if you get the chance and you are physically capable of it.
If I find the time, I would like to climb it again, via the Dunraven Pass Trail. But chances are I'll find my time bogged down with other adventures.