Some distance from the foot of the shaft they came upon a large pit some 150 feet deep which they called Yeitso's Den. The name was later changed to the Devil's Den.
This part of the cave was much as the surging waters of the past several million years had left it. Travel was slow and dangerous. Steep walls had to be climbed and it was necessary to cut steps in the stone. The forward progress was indeed tedious in those early days.
Dr. Lee's report to the National Geographic Society was filled with descriptions of the colorful stalagmites and stalactites, the beautiful formations of flowstone and dripstone, and the subject matter to be seen in the formations all around them. He was equally impressed by the "chambers of unbelievable dimensions," some of which were "several hundred feet wide" and ceilings "so high our lights won't touch them."
He measured the smallest of three rooms which he entered after his journey down the main corridor, which he describes as "slow and laborious." The room measured 160 by 140 feet. "The middle room was three times this size, and the first room was even larger," he said.
He noted the "curtains" formed of onyx created by the deposit of lime carbonate dripping from above. The ceilings were found to be covered with curtains of these stalactites which had grown together during the ages. At times they met with stalagmites to form solid pillars of seemingly carved formations.
At times the floor was rough and covered with fallen blocks of stone. In other places it was quite smooth and flat, obviously the result of years of solutive action by water. Stalagmites do not grow in areas covered for any length of time by water, such as an underground pool. In one place the stalactites were so slender and numerous that Dr. Lee referred to them as resembling "a porcupine in posture of defense."
Dr. Lee's group gave names to many of the rooms and formations, many of which have since been changed. But one which has stuck with all explorers, both before and since Dr. Lee's excursion, is the Big Room. This underground colossus impresses everyone who sees it, and Dr. Lee hesitated to estimate its dimension. "Over half a mile long," he said at that time, "with a ceiling some 200 feet high."
Big as the room was, he felt it was equally remarkable for its numerous dripstone decorations, their variety and size. Some, he noted, rose to 50 feet in height.
He found some stalagmites were still "growing," for they were darker in color than those no longer alive, indicating the presence of water and continued growth. As the supply of water ceases they become lighter in color, almost powdery.
One of the largest he described were the Twin Domes, which he said were more than 100 feet high and some 200 feet across at the base. They are, today, much the same as he first observed them and are one of the favorite formations of all cave visitors.