Sponge Geyser rises as a low, cone-shaped sinter formation, sending up spray and steam beside a small pool, with a dark pine-covered ridge across the open geyser basin behind. The formation sits in Upper Geyser Basin, a short distance from Giantess Geyser, and "strongly resembles a huge sponge in character and color." Its knobby, porous-looking silica deposits explain the name. Yellowstone, established in 1872 as the world's first national park, is known for its dense concentration of geysers and hot springs.
Linen-textured stock with a white border; number 4513 printed at upper left.
No postmark, stamp, or handwriting; unused divided-back linen card. Printed caption on back describes the geyser; light soiling and faint foxing on cream stock.
Cite this card
Sponge Geyser, Yellowstone National Park, WY, circa 1930, postcard, c. 1930. PostalPast Collection. https://postalpast.com/postcard/sponge-geyser-yellowstone-national-park-wy-circa-1930. Accessed November 2, 2026.
