Jacob′s Well is an artesian spring and is the headwaters of Cypress Creek. From this spring, water flows naturally from the Trinity Aquifer directly below. The formation of this spring occurs in a type of rock known as limestone, which is soft, porous and allows the rain water falling in the area to dissolve through the rock and forming what is called a karst cave which leads to an aquifer.

The underground water, as it flows upward from the aquifer is filtered by the limestone rock which causes the water to become crystal clear as it exits at the spring.

The location of the Jacob′s Well is along the Balcones Escarpment and Balcones Fault line. The difference in elevation between the the top of the cliffs (such as at the parking lot elevation) and the bottom of the cliffs (such as at the pool elevation) is an example of the Fault line.

The spring drops vertically down for about 30 to 50 feet before it begins descending at an angle near to 45 degrees to a few more levels until it bottoms out at between 130 and 150 feet. From here the cave travels mostly horizontal for over a mile of passageway, I believe in a northwesterly direction from the well opeing.

During the Cretaceous period, more specifically the Late Cretaceous epoch which occurred between 100 million and 66 million, the land that is now called Texas was covered with a vast inland sea, replete with sea creatures that lived here in these water.

When they died, these creatures left their shells and skeletons behind on the floor of the water and over the course of millions of years, these remains were cemented together in a natural process on the floor of this sea. This process eventually resulted in the limestone that is here today, the rock complete with the fossils contained within in.

Source: 68 °F year round

Perennial Karst spring

1924: 170 gallons per second

Current: negligible flow

Explored and mapped by the Jacob′s Well Exploration Project

Vertically for 30 feet, then at an angle to average 120 feet depth

Secondary cave branches main cave for another 1000 feet

Eight men and one woman.

1699 Mt. Sharp Road in Wimberley, Texas

Reservations reccommended 512-214-4593

Adults: Free

Seniors: Free

Adults: $9.00

Hays County Resident Adults: $5.00

Seniors (60+), Military, Veterans: $5.00

Children (5-12): $5.00