Hoarfrost forms when crystal ice forms directly from moist air to a solid surface. It is crystalline and fragile, not as dense or granular as rime ice. Here, in California's volcanic Long Valley Caldera, steamy air wafted into winter's bitter chill from a geothermal hot creek named...Hot Creek, what else? This process built impressive displays of hoarfrost on blades of grass rising from the stream. Every phase of water was present in the mere span of inches -- vapor, liquid and ice. A winter storm two days earlier generously blanketed the surrounding landscape in snow, and the temperatures outside held in the teens Fahrenheit. The hard freeze combined with the area's small geysers and vents to yield a complex aura of steam, snow, water and frost intermingled. After hiking a short distance from a nearby highway through a couple feet of soft snow (and getting it inside my boots), soaking my cold feet in these waters felt fantastic.
12 ENE Mammoth Lakes CA (20 Jan 6), looking S