If you were in Missoula today, you may have noticed the “M” on Mount Sentinel was bright green, but it wasn't hit by vandals -- it was hit by girl scouts.

They call it "reclaiming the green." More than 100 girl scouts, alumni, and supporters wearing green shirts hiked up the M trail and laid down on the M, transforming the color of the normally white landmark to green. It's how girl scouts across the nation are celebrating the organization's 100th birthday.

Heather Meek, the leader of a girl scout group from Butte, said the very first girl scouts in 1912 wore green uniforms, and now scout leaders are bringing the style back.

"For a while in the 70s, they changed the uniforms to beige and khaki and blue and all sorts of different stuff,” said Meek. “We decided in the last couple of years we're going to reclaim the green, said Meek.