Excelsior Geyser.
Excelsior Geyser, as a dynamic agent, has no equal in the Park. It is really a water volcano, and its eruptions have nothing of the characteristic display of a genuine geyser. Its crater is a vast seething cauldron close by the brink of the Firehole River, into which, in non-eruptive periods even, it pours 4,000 gallons of water per minute. The shape of the crater is irregular. Its dimensions are about 330 by 200 feet, and 20 feet deep. It was not known to be a geyser until 1878, and did not really disclose its true character until the winter of 1881. During the remainder of that year and 1882, it gave continuous exhibitions of its power. Its water column was more than 50 feet in diameter, and at times rose to the enormous height of 250 feet. At such times, it doubled the volume of water in the Firehole River. Its eruptions were frequently accompanied by the ejection of large rocks. A second period of activity took place in 1888, since which time it has remained inactive.
Prismatic Lake is the most perfect spring of its kind in the world. It rests on the summit of a self-built mound, sloping very gently in all directions. Down this slope the overflow from the spring descends in tiny rivulets, every-where interlaced with each other. A map of the mound resembles a spider web, with the spider (the spring) in the center. The pool is 250 by 300 feet in size. Over the lake hangs an ever-present cloud of steam, which itself often bears a crimson tinge, reflected from the waters below. The steam unfortunately obscures the surface of the lake, and one involuntarily wishes for a row-boat, in which to explore its unseen portions. Wherever visible, there is a varied and wonderful play of colors, which fully justifies the name.
Turquoise Spring is another large pool, 100 feet in diameter, and rivals Prismatic Lake in the beauty of its coloring.
The Midway Geyser Basin contains hundreds of other springs, some of them very beautiful, but the Basin is mainly noted for the three features just described.
A TOUR OF THE PARK.
Lower Geyser Basin to Upper Geyser Basin.
Distance, nine miles. Road follows the Firehole River. Midway Geyser Basin, already described, is passed four miles out. No other object of interest is met until the visitor actually arrives at the Upper Basin.