Update: Fire on both sides of McHenry at Stanislaus River grows to 20 acres. Copters assist

4:50 p.m. update: The vegetation fire has grown to about 20 acres since first being reported, said Modesto Fire Department Deputy Chief Darin Jesberg, who’s been assigned to be public information officer for the incident.

The blaze is primarily on the west side of McHenry Avenue. Crews are working to get a containment line around the fire, Jesberg said, and are fighting spot fires to the southwest of it. The rate of spread is slow, but there is a mix of light and heavier fuels.

About 20 units have been committed to fighting the fire, including a task force from San Joaquin County. There are two helicopters and a skid-steer (a small tractor with blade) also being employed.

Stanislaus and San Joaquin counties have a unified command for the fire. Park rangers and the California Highway Patrol also are working the fire.

4:30 p.m. update: Modesto Fire Department Deputy Chief Darin Jesberg is on McHenry approaching the fire scene and said there is no issue with traffic at this time. The smoke is going straight up and not hampering visibility.

A Cal Fire helicopter was requested and is providing reconnaissance, Jesberg said.

Original story: Modesto firefighters are responding to a vegetation fire that is burning on both sides of McHenry Avenue at the Stanislaus River.

Deputy Chief Darin Jesberg said the fire was reported on the west side of the bridge, and there is a northwest wind, so visibility may be affected for drivers in the area.

Shortly after 4 p.m., the fire was about two acres, he said.

This story will be updated as information is available.