Handkerchief Pool -- Yellowstone National Park

This Haynes, divided back postcard of Handkerchief Pool has the date 1923 written on the back, and carries the following caption:

Handkerchief Pool, Upper Basin, Yellowstone Park, is one of many hot springs in the region wherein the convection currents of the water are strong enough to draw a handkerchief downward out of sight, until the upward current catches it and brings it again to the surface.

Handkerchief Pool is located in the Black Sand Basin, along the southern edge of rainbow pool, with which it has underground connections. There are no boardwalks going up to the pool anymore, and the casual visitor would pass nearby without noticing the unremarkable, unmarked thermal feature. Yet at one time it was a major Yellowstone attraction as visitors, often under the approving eye of a park ranger, lowered their handkerchiefs into the pool to have them drawn in and returned "clean" to the surface through another vent. In 1929 Handkerchief Pool became plugged as a result of human abuse. Introducing foreign objects into thermal features for whatever reason is now illegal in Yellowstone, partly because of the lessons learned from this pool.