Yellowstone National Park
Yellowstone National Park has one of the world's largest petrified forests, trees which were long ago buried by ash and soil and transformed from wood to mineral materials. This ash and other volcanic debris are believed to have come from the park area itself as the central part of Yellowstone is the massive caldera of a supervolcano. The park contains 290 waterfalls of at least , the highest being the Lower Falls of the Yellowstone River at .
Summit Lake Park
Summit Lake is a tarn which sits at 12,836 feet (3,912 m) altitude in a glacial cirque on the north face of Mount Evans and the east face of Mount Spalding. To the north, there is a col (12,855 feet/3918 m altitude) looking down into the chain of two cirques holding the Chicago Lakes at the headwaters of Chicago Creek. By one count that includes several unnamed lakes, Summit Lake is the 13th highest lake in the United States. In 1915, the USGS reported that Summit Lake was the highest lake in Colorado, at 12,740 feet. Later secondary sources occasionally report it as the highest lake in the United States.