"The temperature varies in the different pools from fifty degrees all the way up to one hundred and eighty, so there is no difficulty in finding a bath of suitable temperature."
Mammoth Hot Springs
Moran’s Legacy 2: Mammoth Hot Springs — Text by Edwin J. Stanley, 1883
"The first impression on beholding it is that of a snowy mountain beautifully terraced, with projections extending out in various directions, resembling frozen cascades, as though the high, foam-crested waves, in their rapid descent over the steep and rugged declivity, were suddenly arrested and congealed on the spot in all their native beauty. "
A Tale: A Lady’s Visit To The Geysers Of The Yellowstone Park (Part 4) — HWS 1880.
"We traveled over a road made of obsidian, which is a sort of volcanic glass, of a reddish black color, and glistened beautifully in the sun."
A Tale: Army Bicyclists Visit Yellowstone Park — 1896
"They were members the 25th Infantry, U.S. Army Bicycle Corps, a unit of African-American soldiers with white officers."
A Tale: Emma Cowan Visits Mammoth — 1873
"My fairy books could not equal such wonderful tales. Fountains of boiling water, thrown hundreds of feet into the air ... pools of water in whose limpid depths tints of various rainbows were reflected." mounds and terraces of gaily colored sand.”
Early Yellowstone Entrepreneurs
In case you missed, I've posted a link to my Big Sky Journal article on the first intrepid entrepreneurs who tried to turn a dollar in Yellowstone Park.