'Like walking through a forest of ice': Climber finds unique ice pillars atop Mt. Rainier

Penitentes appear near the summit of Mt. Rainier on Aug. 7, 2017 (Photo: McKenzie Johnson)

The view from the top of Mt. Rainier must be incredible, but even the ground can bring some jaw-dropping images.

McKenzie Johnson was climbing near the Mt. Rainier summit Monday morning and spotted hundreds of these pointy 3-4 foot tall ice pillars.

They're called penitentes and begin with a flat snow layer, that undergoes melting at different rates.

Penitentes are only found in high altitude places and "tend to form in shallow valleys where the snow is deep and the sun doesn't shine at too steep an angle," Kenneth Libbrecht, a physicist at the California Institute of Technology in Pasadena who studies ice crystal formation, told National Geographic.

Libbrecht adds that as the snow melts and dirt gets mixed in with the runoff and collects into pools, the darker dirt absorbs more sunlight and melt faster. "And you end up digging these pits," he told the magazine. Some climbers also informally refer to them as "sun cups."

Johnson says the penitentes were dense in some places along Rainier, and spread out in others.

"They are very hard and pretty sharp," she said. "When they are tall it's like walking through a forest of ice."

She says most just consider them melted ice, "but they're actually really special I think."