Dramatic behavioral changes have characterized Porkchop Geyser during the last decade. Once a small hot spring that occasionally erupted, Porkchop Geyser became a continuous spouter in the spring of 1985. The force of the spray caused a roar that could be heard at the museum over 660 yards (603m) away. On September 5, 1989, Porkchop Geyser exploded. Rocks surrounding the old vent were upended and some were thrown more than 216 feet (66m) from the feature. Porkchop Geyser is now a gently rolling hot spring.