Place · 0.1 mi away
Overview
Tucked along the Back Basin boardwalk at Norris, Porkchop Geyser is more about the story than the show. It’s open 24 hours, and today you’ll usually find a hot, gently rolling pool rather than a dramatic geyser. Still, it’s a worthwhile pause on the Norris loop—especially if you like geology with a bit of drama.
Why it’s famous
From a small, irregularly erupting pool, Porkchop turned into a near-constant spouter in the mid-1980s. On September 5, 1989, it underwent a hydrothermal explosion that blew out its silica sinter rim and hurled rocks more than 200 feet. The likely trigger was the failure of a narrow vent “throttle,” causing sudden decompression and flash expansion of near‑surface hot water (a textbook hydrothermal explosion scenario). Since then, it’s mostly settled into a quiet pool within the explosion crater.
What you’ll see now
Expect a near‑boiling, often‑calm pool occupying the 1989 blast crater, with a rim of ejected, jumbled sinter blocks. Interpretive signs typically explain what happened and why Porkchop’s behavior changed. Remember: Norris is one of the park’s most dynamic basins, so appearances can evolve over time.
Best time to visit
Parking at Norris fills late morning through afternoon; go early or late for lighter crowds, cooler temps, and better steam contrast in photos. The boardwalks are open day and night, but always obey any temporary closures—Norris can shut sections without warning when conditions change.
Logistics and safety
- Boardwalk only: stay on it, supervise kids, and keep pets out of thermal areas.
- No services at the feature. Plan on basic restrooms at the Norris Geyser Basin parking area and bring your own water.
- Boardwalks can be wet and slick—wear shoes with grip. On breezy days, scalding spray can blow across the path, so a light shell and eye protection can help.
- Hydrothermal explosions are a real hazard here and elsewhere in the park; never toss coins or objects into features because debris can alter plumbing in dangerous ways.
- Wildlife sometimes wanders through thermal areas; give animals plenty of space and yield if one steps onto the boardwalk.
Pros
- Fascinating hydrothermal explosion history with a visible crater and jumbled blocks
- Easy stop along the Norris Back Basin boardwalk loop
Cons
- Often just a quiet, roiling pool with little action
- No services at the feature; sections can close without notice
Tips
- Visit early or late to avoid Norris parking crunch and crowds.
- Bring water—no running water at the basin parking lot.
- Obey any area closures; Norris boardwalk sections can close without notice.
- Wear grippy shoes; the boardwalk can be wet and slick.
- Stay on boardwalks and never toss objects into the pool.
