Closest entrances and distances: 28 miles from West Yellowstone (west) entrance; 26 miles from Gardiner (north) entrance.

Even if you’ve visited Yellowstone’s oldest, hottest, and most acidic basin before, you haven’t really seen it: The volatile Norris Geyser Basin ★★ changes constantly as old features go dormant, new geysers force their way from the earth, mineral-laden hot springs plug up old tunnels, and earthquakes scramble up the underground “pipes.” Here, heat-loving microorganisms called thermophiles form intricate mats of yellow, green, red, and black among the superhot features; most of the hot springs and fumaroles (steam vents) have temperatures above the boiling point (199[dg]F/93[dg]C at this elevation). In fact, the park’s hottest geothermal temperature ever recorded, a bit more than 1,000 feet underground here, was a blistering 459[dg]F (237[dg]C).

Norris encompasses two loop trails. The shorter one, a .8-mile figure eight through Porcelain Basin, starts with a grand overlook across the baked-white landscape of steaming pools and vents. Highlights include the 20- to 30-foot-high Constant Geyser (despite the name, it’s not always erupting); pulsing Whirligig Geyser; and the hot spring Congress Pool, which might be a hissing dry vent or a boiling puddle. 

Back Basin Loop contains many more features on its 1.5-mile loop trail. The most exciting one is undoubtedly Steamboat Geyser, the world’s tallest at 400 feet. Major eruptions are erratic and rare, but some witnessed it blow its top in 2013 and 2014—so you could get lucky! Echinus Geyser is the biggest known acidic geyser, with a pH approaching vinegar’s. Viewing platforms held crowds when it was a more frequent spouter, but lately Echinus’s shows have been few and far between. A number of other geysers, springs, and fumaroles fill out the basin. 

When you’re through pounding the boardwalks, stop by the stone-and-log Norris Geyser Basin Museum (tel. 307/344-2812) for exhibits on Yellowstone’s thermal features. The building dates back to 1929–30 and also houses a bookstore. Several free ranger programs and hikes take off from here daily in season; check the park newspaper for details. The Museum of the National Park Ranger (tel. 307/344-7353) is worth a stop to see historic photos and information on the evolution of the ranger job. 

Both museums open in mid- to late May, weather permitting, and are open until September; hours vary by season, but you can expect the museums to be open from 9am to 5 or 6pm during the busiest times (roughly Memorial Day to Labor Day, but weather is a factor).

The Norris Campground, which is just slightly north of Norris Junction, is another very popular campground. Its best attribute just might be that it lets you walk to the geyser basin and skip the parking problems of high summer.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.