The New Mexican landscape ranges from wide, auburn-colored deserts to broken mesas to high, snow-capped peaks. Despite New Mexico's arid image, heavily forested mountain wildernesses cover a significant portion of the state, especially towards the north. The Sangre de Cristo Mountains, the southernmost part of the Rocky Mountains, run roughly north–south along the east side of the Rio Grande in the rugged, pastoral north. The most important of New Mexico's rivers are the Rio Grande, Pecos, Canadian, San Juan, and Gila. The Rio Grande is tied for the fourth-longest river in the United States.