Important Dates:

- August 17, 1909 - Earl Douglass, Carnegie Museum paleontologist, discovers eight vertebra of an Apatosaurus, the first skeleton discovered and excavated at the Dinosaur Quarry

- October 4, 1915 - President Woodrow Wilson signs presidential proclamation establishing 80 acres surrounding the Dinosaur Quarry as Dinosaur National Monument

- July 14, 1938 - President Franklin D. Roosevelt signs Presidential proclamation expanding monument by approximately 200,000 acres to include the canyons of the Green and Yampa rivers

- June 1, 1958 - Dinosaur Quarry Visitor Center is dedicated and opened to the public

- 1965 - Monument Headquarters Visitor Center and Harpers Corner tour road are dedicated and opened to the public

Geographic Facts:

- Total Acreage: 210,844.02 acres or 329.44 square miles

- Highest elevation: 9,006 feet at Zenobia Peak

- Lowest elevation: 4,740 feet along Green River in the southwest corner of the monument

- Elevation at Dinosaur Quarry: 5,000 feet

- Elevation at Monument Headquarters: 5, 900 feet

- Highest point on Harpers Corner Road: 7,560 feet at Stuntz Ridge

- Deepest canyon: Canyon of Lodore, over 3,000 feet deep from rim to the river in several places

- Highest cliff: Warm Springs cliff, 1,500 feet

- Yampa River in monument is 46 miles long from Deerlodge Park to its confluence with the Green River

- Green River in monument is 45 miles long from Gates of Lodore to Split Mountain Boat Ramp