Geology and history behind McNeil Quarry Cave explored.

McNeil Quarry Cave is one of the most obscure caves of Austin/Travis County. History and geology of this cave have not been accurately preserved as some of the other caves in the Austin area. This article will explain the history and geology behind McNeil Quarry Cave.

McNeil Quarry Cave is also known as Sam Bass Cave, McNeil Railroad Cave, and McNeil Cave. These are the names this cave has been referred to as and have gone under.

The boundaries of McNeil Quarry Cave are as follows: McNeil Quarry Cave is located north of Howard Lane bounded by the Mountain Pacific Union Railroad and south of the McNeil Post Office. Boundaries of the area for this cave a bounded by the Pacific Railroad to the west, Howard Lane to the south, and another road to the east. These boundaries on a triangular shaped chunk of land.

This cave extends all the way to the city of Round Rock, Texas and connects to another cave called Robbers Cave which is just 3 miles away. McNeil Quarry Cave is a shallow cave. (Ref: Austin Weekly Statesman, Page 3, June 24, 1897)

Terrestrial Isopods are said to live under the rocks of this cave. These Terrestrial Isopods live “under rocks in darkness and twilight zone of the entrance room”. Here Terrestrial Isopods thrive in a dark shaded environment. (Ref: http://www.nativefishlab.net/library/textpdf/20618.pdf)

McNeil Quarry Cave was called “McNeil Quarry Cave” because of its location and proximity near Austin White Limestone Company’s limestone quarries and closeness to the Mountain Pacific Union Railroad. Unsurprising the geology of McNeil Quarry Cave is composed entirely of limestone as is the case with many caves in Texas. So one can expect to see limestone inside of this cave.


Albert Robinson discovered McNeil Quarry Cave in 1861 when he establishing Robinson Ranch. The cave was known first as Robinson Ranch Cave to locals. Albert Robinson owned the ranch land this cave was located on. Keeping people out of McNeil Quarry Cave was difficult to being located on expansive ranch land and rugged terrain.

Now this cave later became known as “Sam Bass Cave” during the 1870s due to the fact Sam Bass and his outlaws used this cave to hide their stolen valuables such as gold and silver. Sam Bass would use the inside of this cave to hide as he evaded law enforcement officials from Travis County and Williamson County along with Texas Rangers. (Ref: Austin Weekly Statesman, Page 3, June 24, 1897)

This “Sam Bass Cave” is not the same Sam Bass Hideaway Cave located on SH 45 in Round Rock. That “Sam Bass Cave” is located in Williamson County while this “Sam Bass Cave” is located in Travis County.

Robinson Ranch Cave was renamed to Sam Bass Cave because the town wanted the cave to be named in the honor of that bandit who terrorized that section of Austin. That is why this cave is named after a notorious outlaw. (Ref: Austin Statesman, Page 11, July 13, 1939)


First signs of wildlife and nature was reported by prominent naturalist J. H. Comstock in 1901 as the first beetle recorded from a Texas cave was found in what was then known as Sam Bass Cave. In 1913, it was described as a new genius and species called Comstockia Subterranea. However this species was later discovered to belong to the Rhacine genus. (Ref: https://digital.lib.usf.edu/SFS0054935/00001)

This cave was later renamed to McNeil Quarry Cave in 1907 when the post and town of McNeil, Texas was established. Austin White Limestone Company acquired more land in Travis County and Williamson County for their mining operations.

Texas Speleological Survey reported in 1958 that McNeil Quarry Cave was then filled almost entirely with trash and garbage. McNeil Quarry Cave could only be explored for about 50 feet by then. Austin White Limestone Company had been using this cave as a trash dump. This cave was said to be located in an artificial ravine near a clump of trees, and consists entirely of a crawlway running under the railroad tracks. Railroad officials have closed because it dangerous by trains passing overhead. (Ref: https://www.texasspeleologicalsurvey.org/PDF/TSS_Volume1/TSS 1(1) compressed.pdf)

Part of this cave has since been paved over sometime during the 20th century as Austin White Limestone Company needed an access road for their limestone quarries. So the entrance may have been paved over, filled, plugged, and blocked by Austin White Limestone Company.

McNeil Quarry Cave is located on Howard Lane, Austin, Texas, US 78727.