Aspen trees grow all over the world, in parts of North America, Europe, Asia, and Africa. The common American variety of aspen tree, Populus tremuloides, generally grows in high-altitude areas above 5,000 feet but also exists at sea level where climate conditions are ideal.
The Populus tremuloides aspen is the most widely distributed tree in North America, growing in a majority of U.S. states and Canadian provinces.
Populus tremuloides is known by the nicknames “trembling aspen” and “quaking aspen” because its leaves appear to flutter or tremble in the breeze.
Rocky Mountain altitudes
In the Rocky Mountains, the trembling aspen grows in an altitude range of roughly 7,000 to 11,000 feet.
The trembling aspen can grow at altitudes as low as sea level, such as in the state of Washington along the Pacific coast and in Maine along the Atlantic coast, where moisture and yearly temperatures are ideal.
The trembling aspen grows as far south as northern Mexico, where it only appears in mountain ranges at elevations above 8,000 feet.