A wildfire in the mountains of California's Santa Clara County has destroyed a dozen homes and consumed about 4,400 acres of forest.

The Loma fire has been burning in the Santa Cruz mountains since September 26, and although it is more than 60 percent contained, it still threatens more than 150 structures, according to Cal-Fire, the state agency in charge of wildfire efforts. Almost 2,000 personnel, including inmate fire crews, are fighting the blaze.

Bryan Martin of Cal Fire said the fire is difficult for firefighters because it's burning through "steep, steep terrain and inaccessible areas."

Despite the remote area, the fire is visible from San Jose. Evacuations are still in place for multiple areas around the blaze, and a local church is serving as a shelter. Another option for residents is a nearby clothing-optional resort that has offered lodging to evacuated people and animals, reports the Santa Cruz Sentinel.

The Loma fire is one of 9 major active blazes burning across California, after a record-breaking heatwave last week and a weather phenomenon known as the Santa Ana wind, which brings hot, dusty air sweeping across the already-desiccated landscape of drought-ridden Southern California.

Although September brings cooler temperatures to much of the country, much of the southwestern U.S. remains hot well into autumn. "Most of CA's most damaging wildfires happen in fall," Cal Fire warned people on Twitter, posting a notice that the top 7 most destructive fires in the state's history all happened in September and October.

The costs associated with fighting wildfires in California are enormous. Farther south, the 130,000-acre Soberanes fire is still burning near Monterey, Calif. That blaze, which has been burning for two months, cost the most to fight of any fire in U.S. history at more than $200 million, according to a recent report by The Associated Press. The cost of battling the flames when the Soberanes fire was at its most intense reached $8 million per day, the U.S. Forest Service told the wire service.

Emily Guerin of NPR member station KPCC reported the cost-per-acre for fighting wildfires in California is already high compared to other states, and it is still growing. She reported that, in 2016, Cal Fire expects to spend the most on fighting fires than it has since at least 2000.

Guerin reports California's population density is one reason for the high cost:

"What makes California's wildfires so expensive? It's primarily that a lot of people live in the wilderness areas, according to Chris Mehl, policy director with the Montana-based nonprofit research group Headwaters Economics. Fire agencies often devote the majority of their resources to protecting homes: between 33 and 90 percent of the cost of suppressing fires is spent on structure protection, according to Mehl."'So it's significant no matter what,' he said. 'But when you get a fire like [the Blue Cut Fire in San Bernardino County], that percentage goes way up because they're using all their resources to try to protect structures and people.'"Compare that to a wildfire, even a much larger one, burning in a remote wilderness area in Montana. Fire agencies may let those fires burn, flying over them a few times a day to monitor them, Mehl said. The idea is that fire is a natural part of the ecosystem, and if it can burn without threatening communities or infrastructure, it should be allowed to do so."Copyright 2016 NPR. To see more, visit http://www.npr.org/.