Mariposa, California (CNN) -- More than 2,000 firefighters rushed Tuesday to save hundreds of homes near Yosemite National Park, which are threatened by a blaze alarming for its size, speed and the fact it's striking so early in California's wildfire season.
The Carstens Fire "is exhibiting extreme behavior to include fire whirls and strong adverse winds," reported California's Department of Forestry and Fire Protection, which is known as CalFire.
That has left many in the affected area on edge, including some told to grab whatever they can from their home and get to safety.
Orlando Vigil is one of them, telling CNN affiliate KGPE that it's been stressful for animals he took from his property to the Mariposa County Fairgrounds. They're safe now, but he's not so sure about his home.
"We'll see if there's anything when when we get back," Vigil said.
Summer wildfires are nothing new in California. But this one is happening weeks earlier than normal, and comes as parts of the state experience "exceptional" dryness that could fuel flames.
"We usually see this sort of fire behavior in August. This is June," said Gary Wuchner, fire spokesman for Yosemite National Park. "It's making us nervous."
The Carstens Wildfire was first spotted Sunday afternoon, after embers from a campfire that hadn't been totally put out spread into surrounding forest.
By Tuesday night, it had burned nearly 1,900 acres, of which 40% was considered contained, according to CalFire. Some 2,200 fire personnel were working the scene, using 53 engines, 11 water tenders. eight bulldozers and other equipment.
At least 800 structures are imperiled by the blaze, with some residents taking up shelter at Mariposa Elementary School. Red Cross officials are there with food, medical help and other basics.
"We also have a mental health worker to help those that are overstressed emotionally from the ordeal of being uprooted from their home," Cindy Thomas of the Red Cross told KGPE.
Not everyone is heeding the calls to evacuate, however.
Among them is Paul "Bear" Vasquez. More than 37 million people have viewed his YouTube video showing him becoming overjoyed and then breaking down at the site of a vibrant double rainbow over a mountain in 2010.
Today, that mountain is singed by the Carstens Fire. But Vasquez says he's staying on the property he bought in 1998, hacking out of the wilderness a spot for the home where he's raised his children.
"I am the protector of this land," he said. "I am part of this place. It has magical powers and I can't leave."
CNN's Miguel Marquez reported from Mariposa, California, and Greg Botelho reported and wrote this story from Atlanta.