The Cave Guide

Mercer Caves

California
161 ft
below the surface
45 min
on the main tour
$24
adult ticket

A California cave with 45-minute guided tours, open daily in summer and Thursday to Monday the rest of the year.

The story

Walter J. Mercer discovered the caverns by chance on September 1, 1885, while prospecting for gold. Early explorers found the skeletal remains of six people, later determined to be members of the Mi-Wuk tribe. The cave was originally named New Calaveras Cave, later changed to Mercer's Cave and in 1946 to Mercer Caverns. The first known commercial tour was held about the same time as the discovery, with guests charged 50 cents for a two-hour tour. In 1985 the cave was designated a Point of Historical Interest by the State of California.

Found
September 1, 1885
Open to visitors since
1885

History source: mercercaverns.net.

What you'll see

  • Cave Twins

Tickets and timing

Adults
$24
Kids
$18 (ages 3–12)
How long it takes
About 45 minutes
Hours
Memorial Day–Labor Day daily from 9am, tours 9:30am–5pm. Rest of the year Thu–Mon from 10am, tours 10:30am–4:30pm. Closed Thanksgiving and Christmas.
Booking
Call 209-728-2101.

Getting around underground

The walk
About a quarter of a mile, with 440 steps total (208 down and 232 up), along steep, narrow stairways; the tour descends to about 161 feet below the surface.

Dogs, weather and what to wear

Temperature
Approximately 55° Fahrenheit year-round, with about 90% relative humidity.

Good to know

Photos
Still cameras with flash are allowed; video cameras and tripods are not allowed.
Food and drink
No food or drinks are allowed into the caverns.
Wildlife
Blind white isopods live in the caverns; squirrels and bats live on the property but not in the caverns.
On site
Visitor's Center, cave-related souvenirs and merchandise

Getting there

Los AngelesSan DiegoSan FranciscoSacramentoFresno

Mercer Caves is in California.

Directions in Google Maps

Distances are straight-line from each city center. The pin marks the nearest town, not the cave entrance.

Questions people ask

How long does a visit to Mercer Caves take?

About 45 minutes

How cold is it inside Mercer Caves?

Approximately 55° Fahrenheit year-round, with about 90% relative humidity..

Do you need to book Mercer Caves in advance?

Call 209-728-2101.

When was Mercer Caves discovered?

September 1, 1885, according to the cave's own history.

Checked on 2026-10-22 against mercercaverns.net (tours page). Prices and hours change, so confirm on the official site before you drive out.

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