Posthole

Indentations in the floor were interpreted as postholes and slots that once anchored wooden furniture.

Source: wiktionary

There, Kate dismounted, postholed through the snow to the door of the Park Service's headquarters, marched down the hall to Dan O'Brian's office, walked in without knocking, sat down without invitation, and said, "Now then. Would you mind repeating to me exactly what you told Ethan Int-Hout this morning?"

Source: wiktionary

Diane and I held our breaths. Good, she was still upright. She slowly moved her weight forward, and picked up her back foot. We exhaled, and she promptly postholed.

Source: wiktionary

The chances of postholing can be minimized by landing with your whole foot at once as well as by wearing shoes with larger outsole surface area to increase flotation marginally.

Source: wiktionary