TERRAIN SLOWS GROUND CREWS : LAKES CLOSED AS FOREST FIRE HITS 1,500 ACRES.

Byline: Patricia Farrell Aidem Daily News Staff Writer

A wildfire sparked by lightning burned into a second day Friday, forcing popular recreational lakes in the Angeles and Los Padres National forests to close and threatening rare toads and fish in natural waterways.

More than 1,500 acres had been charred by late afternoon in harsh terrain accessible only by air transport as the fire burned toward the condor preserve north of Fillmore in Ventura County, U.S. Forest Service officials said.

Up to 10 firefighters at a time were airlifted into the fire area throughout the day, but the force was pulled out both nights as darkness fell, said U.S. Forest Service Fire Division Chief Pat Cooney.

``It's very steep terrain, very rocky,'' said Battalion Chief Terry Molzahn, assigned to the Angeles National Forest's Oak Flat station near Pyramid Lake.

``It's nasty out there,'' Cooney said. ``There are no structures to speak of. The biggest concern is for the firefighters' safety. It's smoky and rocky, really rugged terrain.''

There was no indication when firefighters would either contain or control the blaze. The fire, reported about noon Thursday, is one of a half-dozen blazes in the region torched by lightning. Others burned small patches but were extinguished.

About 250 firefighters camped out Thursday night at a campground near Pyramid Lake in the Angeles National Forest, then relocated to a Castaic Lake campground late Friday.

Three Angeles campgrounds were closed to the public - Oak Flat, Frenchman Flat Campground and Los Alamos.

Firefighting aircraft scooped thousands of gallons of water from Lake Piru to douse flames that climbed steep ridges in the pristine border area of the Los Padres and Angeles forests. Lake Piru was closed because the aircraft posed a hazard.

Then about noon, boaters, swimmers and fishing enthusiasts were ordered to leave Pyramid Lake as aircraft began drawing water there.

Flames moved toward the Sespe Condor Reserve north of Fillmore, but by afternoon Friday posed no threat to the enormous birds reintroduced to the area in a massive effort to prevent their extinction.

Yet rare toads and fish indigenous to the area were threatened as their marshy habitat was swept by flames, fire officials said.

Much of the region hadn't burned since the 19th century, U.S. Forest Service spokeswoman Dianne Cahir said. For forest biologists, the fire is good news because it removes old growth, promotes new vegetation and stimulates the growth of plant that can only germinate with the heat from a fire.

But Cooney predicted a long- term problem: mud flow into Piru, a water source for Ventura County.

``Fire's an important part of Southern California's natural ecology, but that area drains into Lake Piru, and you can expect a lot of mud flow in the next several months into the lake,'' he said.

The Forest Service was joined by firefighters from Los Angeles and Ventura counties.

CAPTION(S):

2 Photos

Photo: (1--SAC only--color) Dense smoke from the fire ha ngs over Pyramid Lake, which was closed Friday as a precaution.

(2--CONEJO and AV only) Fire officials warned people to evacuate Pyramid Lake due to the thick smoke in the recreation area.

John Lazar/Special to the Daily News