Most, if not all, of the smoke choking the sky over the Northern San Joaquin Valley on Wednesday was generated by a raging wildfire in Plumas County, about 170 miles due north of Modesto.
But it was a much closer fire -- burning in hilly and remote terrain at the western edge of Stanislaus County -- that commanded most of the attention of area firefighters.
By nightfall Wednesday, one 17-member Stanislaus strike team had been deployed and a second was en route to the Lick fire, which erupted Monday on the Santa Clara County side of Henry Coe State Park but spilled into Stanislaus County. The cause is under investigation.
"It's burning in very steep terrain near Red Creek and Orestimba Creek," said Stanislaus Fire Warden Gary Hinshaw. "It's into Stanislaus County now, about 18 miles west of Newman."
The California Department of Forestry and Fire Protection reported that the Lick fire was about 25 percent contained at 7 p.m. Wednesday. The fire has burned about 14,000 acres, destroying at least one outbuilding.
Hinshaw said the blaze largely was consuming scrub oaks, digger pines, manzanita and grass over an area that hasn't burned in at least 50 years.
State officials said the fire was threatening 25 homes and 10 barns and sheds.
"There are some hunting camps and ranches in that area," Hinshaw said. "There are some isolated residents (living) there. And there are only a few ways in and out."
Hinshaw said the first Stanislaus strike team was made up of representatives from the Modesto, Ceres, Salida, Turlock Rural and West Stanislaus (Newman area) fire departments.
The second strike team, which gathered in Patterson about 4 p.m. Wednesday for the trip to the base camp in Gilroy, had firefighters from the Woodland Avenue, Oakdale Rural, Mountain View and Stanislaus Consolidated fire departments.
An engine unit from Ripon Fire Department, in San Joaquin County, also was part of the strike force.
1,700 firefighters battling blaze
There are more than 1,700 people battling the blaze, and four firefighters have been injured since the fire broke out; none of them was identified.
Meanwhile, smoke generated by the 15,000-acre Moonlight fire in Plumas County prompted officials at the San Joaquin Valley Air Pollution Control District to issue a "cautionary health statement" Wednesday for residents of Stanislaus, Merced and San Joaquin counties.
By 5 p.m. Wednesday, air district spokesman Anthony Presto said readings for particulate matter indicated that the air quality was unhealthy for people in sensitive groups, including those with chronic lung conditions, in Modesto, Turlock, Tracy and Stockton.
"The fire is sending a large plume of smoke down through the valley and elevating particulate readings in some areas," said Gary Arcemont, an air district meteorologist.
Smoky conditions also were reported in the Bay Area.
Particulate matter -- small pieces of material in the air including soot, ash and droplets of liquid -- can aggravate respiratory conditions and cause asthma attacks.
"If you smell smoke, you are probably breathing it," Arcemont said.
Officials urged residents throughout the eight-county air basin to use caution "as air conditions warrant."
'Probably affecting your lungs'
While today's forecast called for "moderate" air quality conditions, Presto said, people should take precautions if they smell smoke.
"It's very important for people to stay inside if they smell smoke," Presto said. "If you smell smoke, it's probably affecting your lungs."
In addition to the three Northern San Joaquin Valley counties, the air district encompasses Madera, Fresno, Kings and Tulare counties, as well as the valley portion of Kern County.
People with chronic heart or lung diseases were advised to follow their doctors' advice for dealing with unhealthy air quality.
Older adults and children were cautioned to avoid prolonged exposure to the acrid air and curtail heavy exertion or other strenuous outdoor activities.
Officials in Plumas County said the fire had tripled in size from Tuesday night to Wednesday morning, prompting some evacuations of scattered homes in the Lights Creek area.
It grew to about 15,000 acres overnight Tuesday, said Mark Beaulieu, a fire information officer for the Plumas National Forest. While no communities or towns had been evacuated by late afternoon Wednesday, Beaulieu said, some isolated residents had been ordered to leave the area.
The fire, which was 5 percent contained at 4 p.m., was burning along and south of the ridgeline bordering the Plumas and Lassen national forests.
The Plumas fire also prompted a call for additional firefighters to join an estimated 1,000 battling the blaze, the cause of which remained under investigation late Wednesday.
Given the Lick fire, Hinshaw said, it was unlikely that Stanislaus County firefighters would be sent to assist in Plumas, at least for the time being.
The Sacramento Bee contributed to this report.
Bee staff writer Michael G. Mooney can be reached at email@example.com or 578-2384.
Smokes from the Plumas fire spreads
Real-time view from the National Weather Service