Yellowstone was set aside in1872 as the world’s first national park because of its extraordinary geysers, hot springs, mud pots, and fumaroles – more than 10,000 in all. The park’s designation fortuitously also preserved habitat for abundant wildlife, most notably grizzly bears, bison and wolves.

It is today the core of one of the largest intact temperate ecosystems on the planet. With the successful recovery of the bison in the early 1900s and the reintroduction of the wolf in 1995, every species that called Yellowstone home at the time of Lewis & Clark’s Corps of Discovery is still here today. More than 3 million tourists visit Yellowstone each year, with 98 percent seeing less than 2 percent of the park’s 2.2 million acres. The park and river are named for the yellow rocks explorers saw along the river near present-day Billings, Mont.

Visit our photo gallery to view more photos of this spectacular national park and the wildlife within it.

Check out this video on YouTube by National Geographic.

Find out what GYC is doing to protect Yellowstone National Park. Visit our lands, waters, and wildlife issue pages.

Photo credit: Tom Murphy