Virtually half the Paradise Ranch Estates subdivision was consumed by flames Tuesday, with many homes on Sunnyside Drive, Buck Point, Elizabeth Place, Dover Road, Drake's View Drive, and Sunshine Court completely lost.
By Friday, up to 1,200 firefighters had battled the blaze above Inverness Park and in the Point Reyes National Seashore. Only four minor injuries have been reported so far -- all suffered by firefighters.
Fire officials estimated Friday that 80 percent of the blaze was contained, with the full containment not anticipated before midnight Friday.
However, officials were optimistic that the fire would not spread too much further east into populated areas of Inverness and Inverness Park. Battalion Chief Richard Hayes said Wednesday night that at least for now, the most intense part of the fire was headed southwest through the unpopulated National Seashore.
All trails, roads, beaches, and campgrounds within the National Seashore are closed until further notice. West Marin and Inverness Schools, which were closed Wednesday, will be open Thursday.
An evacuation order for the Paradise Ranch Estates subdivision, plus Laurel, Vallejo, Balboa, and Portola avenues remains in effect.
The fire, which officials believe sprang from a small campfire, was discovered on the southern slope of Mount Vision Tuesday at 1:30 p.m. Tiny at first, the flames quickly spread because of 50 mph gusting winds.
Rosevear said the initial blaze was almost contained that afternoon within a one-acre area, but it jumped a canyon south and cut a "narrow swath" southwest across the ridge.
Tomales Bay State Park Ranger Carlos Porrata said the conflagration took off after hurdling the canyon.
"That's where it started getting some really dry material," he said. "As soon as it hit the Bishop pines, it was like an explosion."
He added that there hasn't been a fire on the east side of Inverness Ridge in about 65 years, which has led to a great deal of fuel build-up there.
At about 4 p.m. Tuesday flames reached the houses on upper Sunnyside Drive in the Paradise Ranch Estates subdivision.
With a few isolated exceptions, the fire within hours claimed the entire top half of the steep, wooded neighborhood.
Rosevear said County Fire Chief Stan Rowan ordered a "mandatory evacuation" of about 200 homes in the Inverness Park area at around 4 p.m. Tuesday.
"The evacuation siren was sounded until the power went out," he said.
After burning through Paradise Ranch Estates, the blaze abruptly switched course at about 1 a.m. Wednesday and headed toward the ocean, Tarp said.
During the coolest part of the night, the fire jumped across Limantour Road rolled downhill toward the ocean.
By setting backfires in the blaze's path and bulldozing rings around the buildings, firefighters saved the Point Reyes Youth Hostel, the Clem Miller Environmental Educational Center, and several other structures.
"It just kept coming all the way down to the water," engine driver Larry Devin of Novato said.
Wednesday afternoon, the blaze jumped the southern fire line and continued hurtling south. As of 4:30 p.m., it reached as far south as Woodward Valley Trail.
"The fire jumped past our initial attack force's capabilities," Tarp explained.
He noted that the high, erratic winds have made this fire difficult to predict.
"Normally at night, the wind dies down," he said. "Last night, that didn't happen... Last night the fire was burning better at 2 a.m. than it was in the afternoon."
Crews from Southern California were expected to move in Thursday.
Here too Wednesday were 108 fire engines, 37 hand crews, 16 bulldozers, two spotter planes, seven air tankers, and seven helicopters.
The aircraft, most of which were converted from military use, include a Lockheed Hercules bomber, Bell Huey helicopters, Grumman trackers, a Cessna 02 observation aircraft, and a C-54 converted cargo plane.
The circling helicopters dumped water scooped up from Tomales Bay.
Tarp estimated the current weather pattern, with desultory winds blowing toward the sea but with low humidity, have held.
Tarp said firefighting strategy on the east side of Inverness Ridge involves "direct attack," with hand crews and trucks employing thousands of feet of firehose. Other fighters are digging firelines behind those spraying water.
Porrata said the National Seashore's dairy ranches might serve as one such barrier.
"The ranches have been grazed, so the grass is low and there's very little fuel," he said. "That's good. That's very, very good."
Meanwhile, by Wednesday afternoon, Paradise Ranch Estates was a picture of devastation. Upper Drake's View Drive seemed a stark moonscape. Instead of homes stood an occasional blackened chimney. Trees were reduced to smoking branches. All that remained of cars were smoldering chassis.
"The saddest thing I've witnessed is individuals whose homes were savaged by the floods of 1982 and are now being consumed by fire," he said. "These people are double snake-bit."
Bolinas arborist Ray Moritz said the damage from the fire could continue into winter, as the loss of vegetation could lead to major erosions down the ridge.
"It will take a major effort to stabilize these slopes because we're almost into the wet season," he said. "Many trees are going to fall between now and the end of winter... This is a major ecological event, as well as a catastrophic event for people."
"There is a horrible fire danger on Inverness Ridge," said subdivision resident Harvey Freed last year. "That place is a tinderbox."
Former Planning Commissioner (and former Paradise Ranch resident) Jerry Friedman fought dense development in the subdivision, and noted that Paradise Ranch has been fraught with problems since its inception.
Some of the difficulties have included too many houses -- many of which are made of wood -- plus steep, narrow, and winding roads, and inadequate water systems, he said.
"This is a subdivision with horrifying problems," he said. "It takes 20 minutes for a firetruck to get to the top [of the development]. That's a long time when a house is in flames."
Horizon owner Kevin Daniel said his entire facility, which is located on Sandy Jacobs' property at 200 Sunnyside Dr., is entirely melted.
The Federal Aviation Agency tower on Mount Vision suffered no damage, although its power cables were destroyed. FAA Public Affairs Officer Hank Verbais said the tower, which sends radio signals to commercial and military craft, is functioning -- for now.
(Lori Eppstein, Jennifer Henderson, David Rolland, and Don Schinske contributed to this article.)
