Ruby Canyon

{{Short description|Canyon in Colorado and Utah, United States}}

{{Use mdy dates|date=February 2025}}

Image:Rock formations in Ruby Canyon, as seen from the California Zephyr.jpg

Ruby Canyon is a roughly {{Convert|25|mi|km|abbr=on}} canyon on the Colorado River located on the border of Colorado and Utah in the western United States, and is a popular destination for rafting and overnight camping (permits required).{{cite web | title=Ruby Horsethief Canyon Permits | website=Bureau of Land Management | url=https://www.blm.gov/visit/ruby-horsethief-canyon-permits | access-date=2025-05-24}}{{cite web | title=Ruby-Horsethief Canyon Rafting & Kayaking | website=Whitewater Guidebook | date=2020-04-22 | url=https://www.whitewaterguidebook.com/utah/ruby-horsethief-canyon/ | access-date=2025-05-24}} The canyon takes its name from the ruby-red sandstone cliffs that line its walls.

The only access to the canyon outside of rafting is provided by the Union Pacific Railroad (formerly Denver and Rio Grande Western Railroad) between Mack, Colorado and Westwater, Utah. Amtrak's California Zephyr follows this route through Ruby Canyon between Grand Junction, Colorado, and Thompson Springs, Utah. A popular attraction along the route is the words "Utah | Colorado" painted on the canyon wall at the border between the two states next to the Utaline Siding.