Sight · Yellowstone National Park
A castle-shaped cone, with a major eruption worth a flexible wait.
Overview
Members of the 1870 Washburn expedition named it for its turret-like profile. Up close, look at the uneven walls and the stair-step terraces spreading from the vent; the shape is what makes Castle easy to recognize.
Parkwolf’s verdictWhy it's called CastleMap
Plan your stop
The highest, rockiest slopes around here are a summer buffet for grizzly bears.
Yellowstone Tour Guide
Parkwolf is a GPS audio tour guide for Yellowstone National Park. As you drive, it chimes in with what’s ahead: hidden gems, upcoming stops, history, geology, and wildlife, right through your car’s speakers.
See the Yellowstone audio tourRecorded for this place
Old Faithful and Upper Geyser Basin“You're approaching the Old Faithful area, and I'd make this more than a stop for one eruption. Check the next predicted window at the Visitor Education Center before you start walking.”
Plays as you drive up to Castle Geyser in the Parkwolf Yellowstone Tour Guide.
More stories near here in the app
“First time driving through a national park. We used the Yellowstone tour on grand loop Road and it’s just like having a tour guide in your car with you.”
Guide
Castle Geyser is a tall, broad geyser in Yellowstone's Upper Geyser Basin, known for the turret-like cone around its vent. A short walk on the paved path from Old Faithful brings you to the surrounding boardwalk. It's worth stopping even when it's quiet: the cone and its stepped mineral terraces are unusual on their own.
A major eruption often sends water about 75 feet high for around 20 minutes, followed by a loud steam phase that can last another 30 to 40 minutes. Castle averages an eruption about every 14 hours, but after a minor water-only burst, the next major eruption can't be predicted. Check the park's current geyser predictions and leave room to wait; you may see only the cone if the timing doesn't work out.
Castle's geyserite cone is thousands of years old and rests on older platforms. Together, they make one of the world's largest sinter formations. The park offers a possible explanation for the cone's height: trees may once have become coated in sinter, giving later deposits a taller base. That's a theory, not a settled account.
The boardwalk gives you several angles on the cone. In lower sun, spray or steam can sometimes catch a rainbow, but that's a lucky condition, not a schedule. Keep to boardwalks and designated trails—hydrothermal water can cause severe burns. Shaded benches nearby make this an easy pause.
Wildlife
713 sightingsGrizzly BearMost seen around 6 AMSighting map
743 sightingsWolfMost seen around 6 AMSighting map
5,273 sightingsBisonMost seen around 7 AMSighting map
3,258 sightingsElkMost seen around 7 PMSighting map
397 sightingsMooseMost seen around 7 PMSighting map
1,494 sightingsBlack BearMost seen around 7 PMSighting mapSighting maps show where each species has been reported across Yellowstone. Wildlife moves, so no sighting is guaranteed.
Keep exploring
EasyOld Faithful to Morning Glory Pool Trail2.7 mi · 2 hr · 0.4 mi awayA level geyser walk ends at a spring changed by its visitors.
ModerateObservation Point–Solitary Geyser Loop1.9 mi · 2 hr · 0.5 mi awayA short climb trades switchbacks for Old Faithful from above.
EasyGeyser Hill Loop Trail1.2 mi · 1 hr · 0.5 mi awayCompact boardwalk loop past geysers, vivid springs, and steaming runoff.
EasyFern Cascade Loop Trail2.5 mi · 1.5 hr · 0.8 mi awayA short woods loop slips down to a hidden cascade.
ModerateHoward Eaton Trail: Old Faithful to Lone Star Geyser6.3 mi · 3 hr · 0.8 mi awayBurned hill, spruce-fir forest, and a geyser at the end.
ModerateMallard Lake Trail7 mi · 4.5 hr · 0.8 mi awayPipeline Hot Springs and a Firehole crossing lead to Mallard Lake.
EasyBlack Sand Basin Trail0.5 mi · 30 min · 0.8 mi awayShort boardwalk spurs past colorful hot springs and geysers.
EasyBiscuit Basin Trail0.6 mi · 45 min · 1.7 mi awayA short boardwalk loop through Yellowstone's blue pools and geysers.
Sight · At the trailheadCrested PoolA clear blue spring that boils almost constantly, rimmed in pale sinter
Sight · 0.1 mi awaySawmill GeyserA small geyser with a clear pool and a spinning burst.
Sight · 0.2 mi awayGrand GeyserOne to four bursts, sometimes up to 200 feet high.
Gas station · 0.2 mi awayOld Faithful Gas and Service Station - LowerUnleaded, diesel and a seasonal store in Lower Old Faithful.
Store · 0.3 mi awayOld Faithful General Store - LowerAn 1897 store for a burger and a look at its porch
Sight · 0.3 mi awayLion Geyser ComplexSeven thermal features, but Lion’s eruptions keep no schedule.
Sight · 0.3 mi awayBeehive GeyserA towering plume with no dependable showtime.
Sight · 0.3 mi awayDoublet PoolTwo clear pools, with a pulse that sometimes makes the water jump.Parkwolf’s Yellowstone ranking
The audio tour guide for the drive, plus offline maps, trails, and wildlife heatmaps for when the signal drops.
