Shortly after the sun rose on the Boulder Flatirons Thursday morning, word spread quickly online about two big white words that appeared to be painted on the First Flatiron: “ICE OUT.”

The letters were actually a mesh fabric held up by six climbers on the rock, a Boulder Open Space and Mountain Parks spokesperson told The Denver Gazette.

The words appeared on the northernmost of the iconic Boulder Flatirons around 7:23 a.m., spokesperson Sam Clusman said. A Boulder Police Department drone flying overhead made clear that the words were not paint, as they appeared from afar, but rather letters made of a white mesh-like fabric.

Boulder Open Space and Mountain Parks officials intercepted four of the six involved climbers and interviewed them, but did not issue any citations because the climbers did not attach the letters to the rock.

If the climbers had stepped off-trail, attached the letters to the rock, or accessed closed-off places, there would be legal trouble, Clusman said. However, rangers determined that the climbers stayed on trail, did not attach anything to the rocks and were within allowed hiking boundaries, she said.

When word initially spread, hundreds of commenters on various social media sites flamed the climbers, many of whom commented that they agreed with the messaging, but not with defacing the rocks.

“Ok of course we dig the message yadda yadda, but I REALLY hope that isn’t paint,” one Reddit commenter wrote. “Jesus people. Please don’t be paint.”

Climbing the First Flatiron requires technical climbing skills and gear, and hosts some of the Boulder area’s longest climbing routes, according to Summit Post, a climbing beta website. Climbs can be accessed via popular trails and signed routes.

“I think our community really cares about our open space, so at this point we’re not really worried about others coming to vandalize the rock with messaging,” she said. “I’ll remind everyone to stay on trail and be respectful of our open spaces.”

Last March, Boulder officials removed an upside-down American flag hung on the Second Flatiron, according to a Boulder Daily Camera story.