Not surprisingly, Lassen may be one of the most unique parks you are able to visit due to its landscape transformed by violent geothermal activity over the centuries. Home to multiple volcanoes, steaming fumaroles, wildflower-speckled meadows and much more, it is also one of only two habitats where you will find the Sierra Nevada red fox. If planning a fall visit, be sure to check dates for closure of campgrounds and other facilities in the park. Interested in getting up close with hydrothermal activity? Your best bet is Bumpass Hell which offers a 3-mile round trip trail for exploring steaming and bubbling mud pools and roaring steam vents. Please remember, safety first!