By Dan Whitcomb

(Reuters) - A woman who defaced rock formations in seven U.S. national parks with drawings, then photographed and posted the graffiti on social media has been sentenced to probation after pleading guilty to misdemeanor charges, U.S. prosecutors said on Tuesday.

Casey Nocket, 23, was also ordered to perform 200 hours of community service and pay restitution for the damage, the U.S. Attorney's office in Colorado said. She pleaded guilty to seven misdemeanor counts of damaging government property.

Prosecutors said Nocket used acrylic paints and markers to scrawl on rock formations in national parks in California, Colorado, Utah and Oregon over a 26-day period from mid-September to early October 2014.

She then posted numerous pictures of the graffiti on her social media accounts.

When the vandalism came to light through the blog Modern Hiker, authorities called it one of the most widespread acts of serial vandalism documented in the National Park System.

One picture taken from Nocket's social media accounts and posted on Modern Hiker showed her putting the finishing touches on an acrylic drawing of a cigarette-smoking figure scrawled on a canyon wall at Utah's Canyonlands National Park.

Others showed drawings of a woman with blue hair on a ledge overlooking Oregon's Crater Lake and a bald man with a snake protruding from his mouth on a trailside rock in California's Yosemite National Park.

The graffiti was also found at Rocky Mountain National Park and Colorado National Monument in Colorado, Zion National Park in Utah and Death Valley in California, signed "Creepythings" and dated 2014.

The amount of restitution that Nocket will pay will be determined at a later hearing, prosecutors said.

Nocket was also banned from lands administered by the National Park Service, U.S. Forest Service, Bureau of Land Management and Army Corps of Engineers during her probation.

(Reporting by Dan Whitcomb in Los Angeles; Editing by Jeffrey Benkoe)