Some Points of Volcanic Interest in Yellowstone National Park
http://volcanoes.usgs.gov/yvo/overview.html

U.S. Geological Survey

This U.S. Geological Survey website highlights a few of the many interesting volcanic features related to the Yellowstone volcanic system. Highlighted features include the Obsidian Cliffs, the Grand Canyon of the Yellowstone, Sheepeater Cliffs, and the Mesa Falls ash-flow tuff. An oblique overview map of the Yellowstone area shows the location of these features in relation to other prominent locations around the park.

This resource is referenced here:

• Integrating Research and Education:Yellowstone: Geoecosystem Overview
• Integrating Research and Education:Yellowstone: Solid Earth
• Integrating Research and Education:Yellowstone: Policy and Management
• Integrating Research and Education:Yellowstone: Surficial Geology
• Integrating Research and Education:Yellowstone: Geothermal Environments
• Integrating Research and Education:Yellowstone: Is there a present volcanic hazard?

Subject: Geoscience:Geology:Igneous and Metamorphic Petrology:Volcanology
Resource Type: Audio/Visual:Maps
Theme: Teach the Earth:Course Topics:Petrology
Focus on Yellowstone: Surficial geology and hydrology, Bedrock geology, VolcanismKeyword: caldera