In Zion National Park, up the North Fork, lies the Subway. Canyoneers access it from the "top down", repelling through waterfalls and swimming through pools. Hikers & photographers access it from the "bottom up". There are no official trails, but because of the popularity, many trails braid either side of the river. There are many river crossings to get there, which, depending on the water levels, can be trivial or mid-thigh deep.
Up the famous Narrows in Zion National Park is Orderville Canyon. This is the first of several obstacles.
Ohio Pass is just outside of Crested Butte, CO. Though it generally wasn't a "good" year for fall colors in 2017, there were some very colorful patches to be found