Norris Geyser Basin (Steamboat Geyser & Porcelain Basin) & Artists Paintpots

Located at the central-western crossroads of the Figure-8 Grand Loop Road, Norris Geyser Basin is the hottest, oldest and most dynamic geothermal area in Yellowstone National Park (scientific boreholes here have recorded underground temperatures of 237°C / 459°F just 326 metres below your shoes). Unlike most geyser basins in the world, which are alkaline, Norris is predominantly acidic, producing rare acidic geysers, milky-blue silica pools and lemon-yellow sulphur vents.

1. The Two Boardwalk Loops of Norris: 'Porcelain Basin' vs 'Back Basin'

Both boardwalk loops start from the historic open-air 1930 Norris Geyser Basin Museum (arrive in the early morning or late afternoon in summer, as the Norris car park fills quickly around midday):

1. Loop 1, Porcelain Basin (1.2 km / 0.75 Miles | 30 to 40 Minutes): step out onto the upper wooden overlook to look down on a barren, steaming white-and-orange bowl covered in a mineral deposit called siliceous sinter, which resembles glazed white porcelain. The boardwalk winds through hissing fumaroles like Black Growler Steam Vent, neon-green Cyanidium algae mats that thrive in acidic water, and pools filled with suspended white clay particles that glow an opaque robin's-egg milky blue.
2. Loop 2, The Back Basin (2.4 km / 1.5 Miles | 45 to 60 Minutes, Home to 'Steamboat Geyser'): just 300 metres down the wooded Back Basin path stands Steamboat Geyser, the tallest currently active geyser in the world. While its major 90-to-115-metre water eruptions are unpredictable, it splashes continuously in minor 3-to-12-metre eruptions. Continue around the loop to see emerald-green Cistern Spring and barrel-shaped Echinus Geyser, the largest acidic geyser on Earth.

2. Two Quick Stops Nearby: 'Artists Paintpots' (5 km South) & 'Roaring Mountain' (8 km North)

• Artists Paintpots (1.6 km / 1 Mile Round-Trip, 30 Mins): five minutes south of Norris on the road toward Madison, walk across a flat meadow and up a short hillside staircase to watch thick, pastel pink, beige and grey boiling clay mud pots plop and burp like pots of boiling porridge.
• Roaring Mountain: five minutes north toward Mammoth, pull over beside the road to see an entire bleached-white mountainside steaming from dozens of acid fumaroles.