|Slot canyons within Grand Canyon National Park, or adjacent lands of the Hualapai Reservation.
Most of the hundreds of tributaries that form the side branches of the Grand Canyon are not particularly narrow, rather they are stepped in cross section because of the many strata of differing hardness which cause the upper walls to erode sideways as the canyon deepens. The larger side canyons are very impressive, offering many multi-day hiking routes through remote scenic areas well away from the South Rim crowds, and often there are narrowish sections with typical slot-like features of pools, chokestones, waterfalls and deep water-carved channels, as is the case with Milkweed Canyon. But the best slots are close to the Colorado River in the depths of the main gorge and so not easily accessible by overland hiking; places such as Elves Chasm, Olo Canyon, Travertine Canyon and Matkatamiba Canyon need either access by boat, or overnight hikes and most likely some rappelling.
- Cathedral Wash - short, curving, multi-layered side canyon
- Hindu Canyon - beautiful and very remote narrows on the Hualapai Reservation
- Jackass Creek - colorful, rugged tributary near Lees Ferry
- Milkweed Canyon - limestone narrows and a pink granite gorge
- Tanner Wash - long canyon with unusual passages through thin-layered sandstone
In the far north of the park, downstream of Lees Ferry, the Colorado flows through Marble Gorge, deepening steadily but still on a rather smaller scale than the more well known areas further south. Here the side canyons too are narrower and more intimate and there are several that offer a route to the river. Cathedral Wash is the easiest hike - others may require swimming of pools or climbing down dryfalls. Possibilities include Badger Canyon, Hot Na Na Wash, North Canyon, Rider Canyon, Salt Water Wash, Soap Creek, South Canyon and Tanner Wash. The eastern tributaries on Navajo land are easily reached from US 89 or short side tracks while some of the western canyons are further from the road and involve longer trips on rougher tracks.
In the main part of the Grand Canyon, only a few slots are reachable by road. They include Parashant Canyon in the far northwest, though a long and difficult day hike is needed to get there, and the limestone narrows while quite pretty, are relatively short. Much further east, parts of Kanab Creek and the very lower end of Deer Creek also have nice slots but again an arduous trek is needed to reach them. On the South Rim, the most accessible area is in the Hualapai Reservation, where interesting canyons include Milkweed and Hindu.