Mount Eolus, Mountain summit in La Plata County, US

Mount Eolus is a 14,085-foot (4,293 m) fourteener in the Needle Mountains of the San Juan Range, Colorado, and the highest point of La Plata County. It rises west of Upper Chicago Basin, a cirque it shares with Sunlight Peak and Windom Peak. Its northern subpeak, North Eolus (14,045 ft), has only 179 ft of prominence and is not counted as a separate fourteener.

The peak was first documented during the Hayden Survey in 1874 and received its current spelling from the Wheeler Survey in 1878. These early geological expeditions established the foundation for scientific study of the San Juan Range.

The name comes from Aeolus, the Greek god of the winds. The 1874 Hayden Survey recorded the peak as "Aeolus"; the Wheeler Survey of 1878 first used the spelling "Eolus". The Spanish name Monte Eolo keeps the same god, and variants such as Mount Aeolus and Mount Eoleus also appear.

Mount Eolus sits in the Weminuche Wilderness of San Juan National Forest, 27.4 miles (44.1 km) northeast by north of Durango. It is among the most remote of Colorado's fourteeners, so plan a multi-day trip. The summit is reached from Upper Chicago Basin, where Eolus stands on the west side; Sunlight Peak and Windom Peak lie on the east side. North Eolus, a subpeak of 14,045 ft (4,281 m), is often climbed together with the main summit.

The Northeast Ridge route crosses a section called the Catwalk, a narrow passage combining easier scrambling with steeper climbing. This ridge offers experienced hikers a technically challenging alternative to the standard ascent.