Grand Canyon National Park
On the South Rim, leashed pets are allowed on trails above the rim, Mather Campground, Desert View Campground, Trailer Village, and throughout developed areas.
On the North Rim, leashed pets are only allowed on the bridle trail (greenway) that connects the North Kaibab Trail, and the portion of the Arizona Trail north to the park entrance station.
At Tuweep, leashed pets are only allowed on established roads and the campground
For more information about Grand Canyon National Park see here.
Before You Go Exploring in the USA
For a discussion on state law regarding cats, see here.
Most locations require pets to be on a leash less than 6 feet long.
Typically pets are not permitted in public buildings.
Cats are welcome:
in developed areas
on many trails and campgrounds
in some lodging facilities
Cats must be restrained, either on a leash (not exceeding 6 feet in length) or caged/crated.
Pets are not permitted:
in public buildings
designated swimming beaches
Cats are allowed in national forests, but must be kept on leash (less than 6 feet in length) while in developed recreation areas and interpretive trails.
Cats are not permitted in swimming areas.