Mee Canyon from the Knowles trailhead. They don't 4x4, but it's a cool video and the Mee canyon hike has a trailhead on the Rattlesnake Canyon 4x4 trail / hike; from the 4x4 road you hike down the section they show at 12:00, there's a scary shelf, ladders, holes, all kinds of cool stuff. We've done Rattlesnake Canyon, hoping to do Mee next month.
This is the best hiking website in Colorado, IMO: https://www.gjhikes.com/2017/09/mee-canyon.html