Looking through the 1915 Okla geology journal again.
This picture of a cave entrance is instantly familiar. Along with some nerd buddies, I went through this cave twice in 1970. Apparently the cave was already well known to spelunkers in 1915, though it was never commercialized. We had to go through an oil lease fence to get there.
From the entrance it’s a straight drop of about 10 feet. You had to grab onto that ‘step’ and drop to the floor.
The area just under the entrance is the best part. A big room with thousands of bats and an underground stream with blind fish. The rest of the cave is tricky and dangerous, with a long stretch of worm-like crawling, but not interesting. The cave runs for about a mile, coming out on the other side of the highway.