The flat-topped, glacier-covered Roundtop volcano is the easternmost and lowest of an E-W-trending line of volcanoes on eastern Unimak Island. Roundtop lies 13 km SW of the village of False Pass. The snow and ice-covered edifice fills much of a 3-km-wide caldera that formed during the early Holocene.

Are there any active volcanoes in Pennsylvania?

Today, Pennsylvania has no volcanoes.

Is Roundtop volcano extinct?

Round Top is an extinct volcano in the Berkeley Hills, just east of Oakland, California. The peak lies entirely within the bounds of Contra Costa County. ... The eruptions that lead to Round Top started 10.2 Million years ago and ended more than a million years later.