Located in Arizona, Grand Canyon National Park encompasses 277 miles (446 km) of the Colorado River and adjacent uplands. The park is home to much of the immense Grand Canyon; a mile (1.6 km) deep, and up to 18 miles (29 km) wide. Layered bands of colorful rock reveal millions of years of geologic history. Grand Canyon is unmatched in the vistas it offers visitors from the rim. Open 24 hours.