Old Faithful Geyser, the 1904 Old Faithful Inn & Walking the Upper Geyser Basin to Morning Glory Pool

Named in 1870 by the Washburn-Langford-Doane Expedition for its remarkable regularity, Old Faithful is the most famous geyser on Earth. What surprises first-time visitors most is that Old Faithful is just one of over 150 active geysers packed into a single 2.5-square-kilometre valley: the Upper Geyser Basin, which holds a quarter of all the geysers in the world along a flat, 4-kilometre boardwalk loop.

1. How to Time Old Faithful & Tour the 1904 'Old Faithful Inn'

• How Often Does Old Faithful Erupt? (Every 90 to 94 Minutes, +/- 10 Minutes): depending on the duration of the previous eruption (1.5 to 5 minutes), rangers predict the next eruption with 90% accuracy. Check the live boards inside the Old Faithful Visitor Education Center or the Old Faithful Inn Lobby, or check the NPS Yellowstone App. Each eruption shoots 14,000 to 32,000 litres of 95°C boiling water 32 to 56 metres into the sky.
• 2 Ways to Watch (The Boardwalk Bench vs 'Observation Point' Hike): watch one eruption from the ground-level semicircle benches, or cross the Firehole River bridge and hike 1.1 km (60m gain, 20 mins) up the switchbacks to Observation Point to look straight down on Old Faithful with the entire Geyser Basin behind it.
• Step Inside the 1904 Old Faithful Inn (Second-Floor Deck Drinks): walk into the 7-storey-high (26-metre) lodgepole-pine lobby around the 500-tonne, 8-hearth stone fireplace, and grab an ice cream or drink to sit in the rocking chairs on the second-floor outdoor viewing balcony facing Old Faithful.

2. Walk the 4.5-Kilometre Loop to 'Morning Glory Pool'

Most bus tours watch Old Faithful and leave immediately, missing five geysers that are even taller or more colourful. Before starting your walk, photograph the predicted eruption windows for the other five major geysers (Grand Geyser, the tallest predictable geyser in the world at 60m, Castle Geyser, Riverside Geyser, Daisy Geyser and Grotto Geyser) on the Visitor Center board, and walk the flat boardwalk loop past sapphire-blue Beauty Pool and Chromatic Pool all the way to the glowing emerald-and-gold funnel of Morning Glory Pool.