Lone Star Geyser is a cone geyser that erupts approximately every three hours. Though the height of the eruption is not as tall as the nearby Old Faithful Geyser, it does erupt considerably longer—up to 30 minutes. The eruption can reach heights of 35 to 40 feet (11 to 12 m). The intensity also fluctuates during the eruption, going up and down, then back up again.
The geyser is in a picturesque spot, located in the forest near the Firehole River. The runoff channels run down to the river, with colorful bacteria mats. Nearby you will hear and see small fumaroles. If you arrive between eruptions there are shaded spots to sit under the nearby trees.
Just prior to the eruption there will be little displays of water and steam. These will continue in frequency and size until the main eruption occurs.
The geyser is not as heavily visited as Old Faithful due to the hike and semi remoteness, but the show it makes is worth the effort. The trail is an easy hike, not too strenuous. It is an old service road for most of the 2.4 miles.
Near the geyser is a pedestal containing a log book of eruptions. Check the log to get an idea of when the next eruption could occur. Be sure to update it with your eruption time so the next guests can calculate the next eruption.
Know Before You Go
The trail head is approximately 3 miles south of Old Faithful, heading towards West Thumb/Lake Yellowstone. If the parking lot is full, park at the nearby Kepler Cascades parking lot. The hike is about 4.8 miles (7.7 km) round trip. Pack plenty of water and a snack. Biking is permitted on the trail, but they are not permitted past the barrier near the geyser. Be sure to carry insect spray and bear repellant. Yellowstone now rents bear repellant - check for details at any of the visitor centers.