Satellite showing possible new fire start in Marin County. Near Hwy 1 and Sir Francis Drake Blvd. Dark purple is possible heat signature. #cawx pic.twitter.com/4Rb2x6Skwz — NWS Bay Area (@NWSBayArea) September 11, 2018

An evacuation order is in place for Mountain King Rd, Portola Ave and Alamo down to Barranca. Residents in that area should evacuate immediately to the Lagunitas School and wait for further information. Alamo Rd. will be closed until further notice. pic.twitter.com/0eqevGsb83 — Marin County Fire (@marincountyfire) September 11, 2018

Reminder: monitor local news media outlets and follow any further instructions if given by Marin County Fire or Marin County Sheriff. Smoke may be strong in surrounding communities. The Fire Public Information Hotline has been updated: 415-473-7191 pic.twitter.com/0DoIAEBp1E — Marin County Fire (@marincountyfire) September 11, 2018

#IrvingFire Update: Fire at 100 acres, 10% containment. Fire crews are dealing with very steep terrain, but beginning to build momentum on containment. Using a combination of bulldozers, hand crews, water tenders and engines in the firefight. #WestMarin pic.twitter.com/CYhy5m7kII — Marin County Fire (@marincountyfire) September 11, 2018

LAGUNITAS, Calif. (KGO) -- A 100-acre wildfire burning in a park in Marin County Monday night prompted evacuation orders, according to fire officials.The fire is burning in the Samuel P. Taylor State Park in an area difficult for firefighters to access. It was first reported around 8 p.m. At least 20 to 30 structures are being threatened and the fire was 10 percent contained as of midnight.Evacuated residents were advised to go to the Lagunitas School and await further instructions.Smoke in the San Geronimo and Fairfax communities could be strong due to the fire.Find the latest evacuation information from the Marin County Fire Department Some road closures are also in effect, and a public information hotline has been set up for residents to call.