Cory Linfield posted the trail:

The Rainbow Trail is one of the longer hiking trails in Colorado, after the Colorado Trail and the Colorado section of the CDT. It runs roughly parallel to the Sangre de Christo mountains in the South Central part of the state, starting at one end south of Westcliffe and at the other end south west of Salida, forming an upside-down J. The trail is roughly 100 miles long with around 24,000 ft of gain according to a TOPO! map of the route. 

Jared Campbell keeps a (long!) list of Wasatch area FKTs here. Includes running, scrambling and some climbing as well.

Here's how one publication describes Siphon Draw & the Flatiron, in Lost Dutchman State Park (east of Phoenix):

Jessica Kelley posted this well-known route:

The Press Traverse is a relatively well-known north-south route across the Olympic Mountains, first completed by European explorers in 1890. These explorers were sponsored by the Seattle Press, and therefore their trip was called the Press Expedition, and their route became known as the Press Traverse. It took the original Press Expedition six months to blaze a trail through the heart of the Olympics.