Drivers heading north on Petaluma Hill Road have for the past year received fire prevention tips on a sign posted on a patch of grassland just outside the Santa Rosa city limit.

However Monday morning the message was covered with a tagger's moniker scrawled in black paint.

"This is a punch in the gut for us," said Cyndi Foreman, fire prevention officer with the Rincon Valley Fire Department.

A similar moniker appears on several buildings along Petaluma Hill Road.

Staff and volunteers with the fire department and Cal Fire had collaborated to buy and build the sign last year, Foreman said. They alternate messages encouraging people to clear brush close to their homes, use carbon monoxide detectors, clean chimneys, keep flammable items away from heaters and other fire prevention wisdom.

The current sign is designed to look like a post card sent to Sonoma County residents to remind them to plan how to escape their home in the case of fire.

"Practice E.D.I.T.H.," which stands for exit drills in the home, the sign reads under the graffiti paint.

"I put my heart and emotions into this message because I'm very passionate about it," Foreman said.

The sign was built for about $800 and posted along the road on a 14-acre plot of land managed by the Sonoma County Agricultural Preservation and Open Space District south of Yolanda Avenue.

Fire department staff will paint a new message, Foreman said.

"We really rely on this to get important messages to the public," Foreman said. "It's really not a huge dollar loss, it's just a shame."