1. On June 27, 1905, construction began on the Cheesman Dam, which was built to supply the growing city of Denver with water. The dam was completed in 1909 and impounds the South Platte River to form Cheesman Lake.

2. In 1949, the Black Canyon of the Gunnison National Monument was established on June 27. The monument protects a rugged and remote section of the Black Canyon, a narrow and steep-walled gorge cut by the Gunnison River.

3. On June 27, 1976, the Grand Mesa National Forest was officially established. The forest covers over 800 square miles in western Colorado and is known for its high mesas, lakes, and extensive network of trails.

4. In 1994, a wildfire known as the South Canyon Fire broke out on June 27 near Glenwood Springs. The blaze, which was caused by lightning, eventually burned over 2,000 acres and claimed the lives of 14 firefighters.

5. On June 27, 2012, a massive wildfire known as the Waldo Canyon Fire erupted near Colorado Springs. The blaze burned over 18,000 acres and destroyed 346 homes, making it one of the most destructive wildfires in Colorado history.