Mount Aetna is set 1.5 miles (2.4 km) east of the Continental Divide in the Sawatch Range which is a subrange of the Rocky Mountains.

The prominent mountain is located 19 miles (31 km) west of the community of Salida on land managed by San Isabel National Forest.

[7] A visually prominent talus gully on the south slope of the mountain creates an illusion of lava flowing down this pseudo-volcanic peak.

[5] The mountain's toponym has been officially adopted by the United States Board on Geographic Names,[4] and has been featured in publications since at least 1910, if not earlier.

[9] Due to its altitude, it receives precipitation all year, as snow in winter, and as thunderstorms in summer, with a dry period in late spring.