In 1915 President Woodrow Wilson established Dinosaur National Monument, to preserve 150 million year old dinosaur fossil beds, discovered by paleontologist Earl Douglass in 1909. In 1938 the monument boundaries were expanded from the original 80 acres area surrounding the fossil beds—now known as Douglass Quarry—to over 200,000 acres.
The monument also preserves cultural history that dates back 10,000 years. Native American petroglyphs and pictographs provide evidence that many groups have made this arid land their home. The Fremont Indians lived in the canyons 800 - 1,200 years ago, followed by the Ute and Shoshone, who still reside in the area today.