The San Diego County Sheriff's Department issued an evacuation warning Tuesday for portions of North County near the Riverside County line because of the Nixon Fire.
The blaze remains contained within Riverside County, but if conditions change, it could extend into San Diego County.
Residents near the Warner Springs area should be prepared to leave, the department said.
Due to the growth of the #NixonFire burning in Riverside County, an EVACUATION WARNING is being issued for portions of Northern #SanDiegoCounty (yellow areas) seen in the map below.
— San Diego Sheriff (@SDSheriff) July 31, 2024
Residents in these areas should be prepared to evacuate should fire conditions change.
An… https://t.co/ADlIDZ3mem pic.twitter.com/TJfSMXoowq
A brush fire south of Highway 371 in Aguanga has grown to over 4,900 acres Wednesday, burning into a federal preserve along the boundary separating Riverside and San Diego counties with 0% containment but no further immediate threat to homes or other structures.
The non-injury Nixon Fire was reported at 12:28 p.m. Monday in the area of Richard Nixon Boulevard and Tule Peak Road, according to the Riverside County Fire Department.
The agency said numerous engine and hand crews — numbering over 250 personnel — from the county, Cal Fire-San Diego County and other agencies were sent to the location and encountered flames burning at a "dangerous rate" to the southeast through medium brush.
As of Tuesday morning, the head of the fire was well inside the Beauty Mountain Wilderness, near Iron Spring Mountain, maintained and protected by the U.S. Bureau of Land Management.
According to Cal Fire officials, the flames scorched more than 4,900 acres as of 8 p.m. Tuesday as firefighters continued efforts to stop the fire's progression throughout the night.
Supervisor Kevin Jeffries, a former firefighter, asked Riverside County Fire Department Chief Bill Weiser at Tuesday's Board of Supervisors meeting if containment efforts might be complicated because of federal restrictions on using heavy machinery, such as bulldozers, to battle blazes in protected areas.
Weiser said he did not anticipate problems, and coordination with Bureau of Land Management administrators was "good."
At the height of the fire, seven Cal Fire air tankers and four water- dropping helicopters were making runs on it. On Tuesday, aircraft were only required for targeted operations.
Four structures were damaged and one was destroyed Tuesday afternoon, but it was still unclear whether those were only sheds and outbuildings, or may have included homes.
An evacuation order was implemented for the scattered homes south of Highway 371, north of the county line, west of Terwilliger Road and east of Foolish Pleasure Road.
An evacuation center was established at Temecula Valley High School. However, county Emergency Management Department Director Bruce Barton told the board there was no one utilizing the space, which is being managed by the Red Cross and Department of Public Social Services.
Winds shifted due to the hilly terrain, complicating firefighting efforts on Monday, forcing crews to spread out and try to establish structure protection lines. The winds were not intense Tuesday morning.
Properties in the remote location are spaced acres apart.
Shortly after 4 p.m. Monday, the blaze spread into the 2,300-acre burn scar from the Bonny Fire that crews battled for over a week last July and August in Aguanga. Weiser said the scar was aiding in slowing the growth of the brusher because there was less fuel to feed it.
The cause of the fire was under investigation.
