Dyer Mountain is a high mountain summit in the Mosquito Range of the Rocky Mountains of North America. The 13,862-foot (4,225 m) thirteener is located 5.9 miles (9.5 km) east (bearing 95°) of the City of Leadville, Colorado, United States, on the drainage divide separating San Isabel National Forest and Lake County from Pike National Forest and Park County. The mountain was named in honor of frontier preacher John Lewis Dyer.