"About two hundred yards from this cave is a most singular phenomenon, which we called the Muddy Geyser. It presents a funnel-shaped orifice, in the midst of a basin one hundred and fifty feet in diameter, with sloping sides of clay and sand. The crater or orifice, at the surface, is thirty by fifty feet in diameter. It tapers quite uniformly to the depth of about thirty feet, where the water may be seen, when the geyser is in repose, presenting a surface of six or seven feet in breadth. The flow of this geyser is regular every six hours. The water rises gradually, commencing to boil when about half way to the surface, and occasionally breaking forth in great violence. When the crater is filled, it is expelled from it in a splashing, scattered mass, ten or fifteen feet in thickness, to the height of forty feet. The water is of a dark lead color, and deposits the substance it holds in solution in the form of miniature stalagmites upon the sides and top of the crater. As this was the first object which approached a geyser, we, naturally enough, regarded it with intense curiosity....
"While returning by a new route to our camp, dull, thundering sounds, which General Washburn likened to frequent discharges of a distant mortar, broke upon our ears. We followed their direction, and found them to proceed from a mud volcano, which occupied the slope of a small hill, embowered in a grove of pines. Dense volumes of steam shot into the air with each report, through a crater thirty feet in diameter. The reports, though irregular, occurred as often as every five seconds, and could be distinctly heard half a mile. Each alternate report shook the ground a distance of two hundred yards or more, and the massive jets of vapor which accompanied them burst forth like the smoke of burning gunpowder. It was impossible to stand on the edge of that side of the crater opposite the wind, and one of our party, Mr. Hedges, was rewarded for his temerity in venturing too near the rim, by being thrown by the force of the volume of steam violently down the outer side of the crater. From hasty views, afforded by occasional gusts of wind, we could see at a depth of sixty feet the regurgitating contents."