The tallest mountains to the west of the Mississippi River are amid the Sierra Nevada range. This mountain chain lies along the west coast of the United States in California. Its highest point is also the highest elevation above sea level in the lower 48 states.
At 14,505 feet (4,421 meters), Mount Whitney is the tallest point in the Sierra Nevada, and is 21 meters taller than the highest point in the Rocky Mountains. Due to its height, this mountain range played a major role in constraining the expansion of the first colonists of the region, who spread west from the Mississippi Basin.