Famed for their ruggedness, spectacular scenery, and world-famous natural features seen at Yellowstone, the Tetons, and Pikes Peak, the Rockies stretch from Canada into northern New Mexico. Along their length, these alpine habitats are full of an astounding array of plants and animals. The Rocky Mountains are broken into four ecoregions, as designated by the Environmental Protection Agency: The Northern Rockies stretch from northern Idaho and Montana into northern Alberta; the Middle Rockies extend from central Idaho and Montana into Wyoming and Utah; and the Southern Rockies encompass the Colorado Rockies, the ranges in northern New Mexico, and several isolated ranges in eastern Utah. A fourth ecoregion includes the high peaks in Arizona and southern New Mexico. While sharing many similarities with the Southern Rockies, this ecoregion is distinct, with unique geology and biology.