A-0 Geyser

A-0 Geyser is a hot spring in Yellowstone National Park that periodically ejects water and steam. The feature sits within an area containing numerous similar thermal eruptions that showcase the park's volcanic system.

The structure formed millions of years ago through volcanic processes that shaped Yellowstone's landscape. Scientists began systematically studying such springs once the park was established in order to understand these natural phenomena.

The geyser's name reflects its role in the park's monitoring system, where researchers catalog thermal features across the landscape. Visitors can observe how scientists track activity here and understand why such locations matter for studying Earth's natural processes.

The area is accessible year-round, though visibility varies depending on season and weather conditions. In winter, steam eruptions are particularly visible against cold air, while trails may have snow coverage.

The geyser was named using a letter system that researchers employed to catalog and track hundreds of springs throughout the park. This practical naming approach allowed scientists to quickly distinguish between the many similar features in this volcanically active area.

Location: Wyoming

GPS coordinates: 44.54310,-110.79600

Latest update: December 14, 2025 14:40