Hiking trails in Yellowstone

We, too, are hikers. In our experience with multiple visits to Yellowstone, once you get away from the short geyser, mud pot walks and get on a real trail, you will only see a few people. Most do not come to Yellowstone to hike but they're missing out on some great views. :) Here's the official Yellowstone site which covers a lot of park information - good readying. It also gives some hiking information and there are many books to purchase with hiking information.

http://www.nps.gov/yell/planyourvisit/hiking.htm

I hope you're also planning to visit nearby Grand Teton Nat'l Park. That is where we really enjoy hiking.

http://www.nps.gov/grte/planyourvisit/hike.htm