The Grand Canyon in the mid-western United States is a steep-sided cut in
Earth's surface that is 277 miles long and up to a mile deep. It was formed by
the force of
Glacier National Park in Montana contains U-shaped valleys where large
glaciers scraped away rock and sediment from the side of mountains. These
valleys were formed by the force of
Monahans Sandhills State Park in West Texas has sand dunes up to 70 feet
high. The dunes were formed from the force of
The Mississippi River Delta on the southern coast of Louisiana has spread 15 to
50 miles into the Gulf of Mexico over the last 5,000 years. It was formed from
the force of