The state with the most national parks in the Southwest United States is Utah.

Utah is home to five national parks, often referred to as the "Mighty 5": Arches, Bryce Canyon, Canyonlands, Capitol Reef, and Zion. These parks are famous for their stunning desert landscapes, towering rock formations, and unique geological features. Utah's national parks attract millions of visitors each year, drawn by opportunities for hiking, photography, and outdoor adventures amidst some of the most breathtaking natural scenery in the United States.