Outlaw Arch

NABSQNO 12T-675990-4486380 Colorado MAP

Outlaw Arch
Outlaw Arch, Dinosaur National Monument, Colorado
Photo by Scott Patterson.


Big 16 Tour

On September 3, 2006, the rock climbing team of Scott Patterson, Adam Pastula, Michael Kelsey, and Stephen Ho got quite a surprise. Rappelling into a remote, isolated canyon in western Colorado, they found themselves next to a huge natural arch. Back home, Patterson reported the find to NABS, asking if it was known. It wasn't. He also estimated its span at over 200 feet.

Armed with advice on how to properly measure it, Patterson returned to the arch with Jeff Fox and a steel tape on September 30. Sure enough, even though the opening narrows to a separation of about a foot at some places, the gap between lintel and cliffwall has a horizontal length of about 206 feet. Thus, Patterson and friends have provided the most recent documentation of a natural arch verified to have a span over 200 feet. They named it Outlaw Arch after Outlaw Park, a well-known flat nearby on the Yampa River.

Outlaw Arch is a young alcove arch eroded through Weber Sandstone, part of the lower Permian. It is located in a remote section of Dinosaur National Monument in Moffat County, Colorado. Access requires a very strenuous hike that crosses the Yampa River and involves some pretty serious technical climbing. Its remoteness and difficulty of access, as well as its small separation from the cliff behind it (keeping it from being spotted from the air), is the reason such a large landform went unnoticed for so long.

Outlaw Arch

This photo by Scott Patterson from above shows the arch toward the left of the photo, casting a large shadow on the cliff below it. For complete route descriptions and more photos, see Scott's web pages here:

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The Natural Arch and Bridge Society