The Yellowstone caldera has been eroded, filled in with lava flows and ash from smaller eruptions (the most recent was 70,000 years ago) and smoothed by glaciers.

• 黄石公园的破火山口被一些小型喷发的熔岩流和火山灰侵蚀（大约70,000年前），后来又因降温而冷却。