Val Verde County · 29°32.21′N 101°15.18′W
Goodenough Spring
Texas' third-largest spring until Amistad Dam was completed in 1968 and the
reservoir drowned it. Under artesian pressure it discharged 100–200 cubic feet per second, and
it still runs — now beneath the lake.
Its depth is not a fixed number. Published accounts put the mouth around 165
feet below normal pool level; the original CAVEDIVER.COM notes recorded 100–110 feet at the lake
levels of the time. Both are right — depths here are measured from a reservoir surface that
moves, and a restriction logged at 152 ffw was later found beyond 200 ffw.
Read the site notes.
The Goodenough Springs Exploration
Project has been pushing the system for years, and it was for a time recognised as the
deepest known underwater cave system in the United States.
Conditions are unusual: visibility in the reservoir outside the cave runs
only 1–5 m, while inside it frequently exceeds 30 m. Flow has been strong enough that
divers have used mountaineering technique to make headway.
Reeves County · West Texas
Phantom Springs Cave
Near Balmorhea, and now believed to be the deepest underwater cave in the United
States. A 2013 expedition led by Texas A&M Galveston marine biologist
Tom Iliffe reached 462 feet — and still did not find the end
of it.
The spring feeding it is part of the same system that supplies the pool at Balmorhea State
Park, an anomaly in the middle of the Chihuahuan Desert.
Access is severely restricted — only two permits are ever issued
concurrently. The cave is habitat for the endangered Comanche Springs pupfish and Pecos
gambusia. Divers have died here. Do not treat it as a destination.
Crockett County
O-9 Well
A multi-drop shaft on the Edwards Plateau, around 100 metres (328 feet)
deep, requiring rope proficiency as well as dive capability. A long-standing fixture of Texas
cave diving and the subject of exploration in its upstream passage.
It has a surface history too — a stop on the Ozona-to-San Angelo stagecoach line and on cattle
drives running from Mexico toward Kansas City. A windmill still draws water from it.
Managed by the Texas Cave Management Association for the University Lands system.
Visitation is restricted to TCMA members — arrange access before you travel.
Del Rio · Val Verde County
San Felipe Springs
A group of springs running about two miles along San Felipe Creek northeast of Del Rio, and
among the largest spring systems in Texas. Average flow between 1889 and 1977 was roughly
41,000 gallons per minute.
Curiously, the Amistad impoundment that drowned Goodenough increased the flow here.
The springs are the sole water supply for the city of Del Rio and Laughlin Air Force Base, and
the creek is home to the San Felipe gambusia, found nowhere else.
Documented in Underwater Speleology, December 1976 — among the
earliest published Texas cave diving accounts held in the archive.
Amistad
Amistad Reservoir
Administered as a National Recreation Area, the reservoir covers a considerable stretch of
karst country either side of the international border. Goodenough is its best-known submerged
spring, and access is subject to National Park Service rules.
Gulf Coast
Offshore & the rigs
Texas technical diving has always had a second life offshore — deep-water rig and artificial
reef trips out of the Houston and Galveston area, and work on the Flower Garden Banks, run
alongside the cave diving by the same small community.