I spent last week on vacation; I hiked 35 miles from the Cascade Pass trailhead to Stehekin. I planned for it to take most of a week, but finished the hike in 3 days, which gave me time to explore my destination. Part of how I did that was by bike.
Renting a bike in Stehekin feels a little crazy after living in Seattle, they're very nonchalant about it. You don't need an ID (mine was in my car, I didn't want to lose it) or a deposit. You're supposed to lean your bike against a tree when you're not using it, leave it behind and out of sight, and not worry. They said they've been in business for 30 years, and never lost a bike. It cost $15 to rent one for half a day.