Originally Published: 31 AUG 21 03:09 ET

Updated: 01 SEP 21 01:48 ET

By Kelly McCleary, CNN

(CNN) -- The governors of California and Nevada declared states of emergency Monday as the fast-moving Caldor Fire, now the 17th largest wildfire on record in California, prompted officials to tell everyone in the city of South Lake Tahoe to get out.

In California, Gov. Gavin Newsom declared a state of emergency in Alpine, Amador and Placer counties, which surround the Lake Tahoe region, his office announced.

The Caldor Fire has consumed 191,607 acres since it began on August 14, according to Cal Fire. It is 16% contained.

Nevada Gov. Steve Sisolak also declared a state of emergency Monday in anticipation of flames from the Caldor Fire crossing state lines in the coming days.

The declaration "ensures resources from the local, state, and federal levels are available to assist as needed during this emergency," a statement from Sisolak's office said.

The efforts to optimize resources come as the fire raced toward the vacation enclave of Lake Tahoe, which straddles the California-Nevada border.

The entire city of South Lake Tahoe and the southern portion of the lake were put under mandatory evacuation Monday.

"There was a huge amount of granite between the fire and us and I woke up on Sunday and it had, it had jumped that granite and now it is in the Lake Tahoe basin and homes are threatened and our community is threatened and I never thought that was possible." said Mayor Tamara Wallace.

The town's residents, about 20,000 people, left Monday. Wallace added there is no discussion about when residents will be allowed to return.

"Right now, the fire is raging through the Lake Tahoe basin, and we're not even considering talking about that," dismissed Wallace. "We're just right now trying to see what happens with the structures and businesses in our community and our homes." The city council will meet tonight remotely as their emergency operations center has moved to nearby Nevada.

Inmates at the South Lake Tahoe Jail were also evacuated, the El Dorado County Sheriff's Office said.

The fire was active overnight and embers traveled up to three quarters of a mile, according to the incident report. Strong winds tested control lines and the area is under a red flag warning through Wednesday night, according to the incident report.

"We do have very active fire behavior, spotting, and torching and very dry fuels under these drought conditions and we expect this active firefight to continue over the next couple days under this weather condition," warned Cal Fire Chief Brian Newman at a press briefing Monday night.

"Three-and-a-half hours of being stuck on Highway 50, I'm so appreciative that our citizens listened to the warning and the order and evacuated the city," marveled South Lake Tahoe Police Chief David Stevenson. "Their response was fantastic and I appreciate them. I'm glad to know they are safe," he said, grateful residents heeded the evacuation orders Monday.

"As many of you are aware, we are seeing larger and more destructive fires burn throughout California on a much more frequent basis. Historically, we've used the terms such as anomaly, unprecedented, or extreme to describe the wildfires that we have seen burn throughout the state over the last 20 years. These terms are no longer appropriate given the clear trends associated with drought, changing climate," lamented Cal Fire Chief Chris Anthony. "Unfortunately, these factors contribute to the resistance to control that we're seeing with the Caldor Fire," he reasoned. "Many people, including myself, consider the Tahoe Basin a unique treasure and a natural wonder of the world whether you live here full time, own a second home here, visit the basin during family vacations, or simply recreate here, there are simply hundreds of thousands of people who hold Tahoe dear to their heart."

The fire destroyed 486 homes and threatens 33,679 structures.

Cal Fire estimates full containment by September 13. The cause of the fire is under investigation.

Roads in the area quickly became clogged with traffic as residents scrambled to leave.

The evacuation order covers more than 53,000 residents in El Dorado County, which includes South Lake Tahoe, according to the California Governor's Office of Emergency Services.

Barton Memorial Hospital in South Lake Tahoe evacuated its patients Sunday to partner facilities in the region, the hospital said in a tweet Sunday night. The hospital said Monday it was closing all services and medical offices, including its urgent care and emergency department.

So far, the Caldor Fire has destroyed 664 structures -- residential, commercial or otherwise -- according to Cal Fire. Nearly 40 structures have been damaged and five injuries are reported, officials said.

The fire is being fueled by dangerously dry conditions as California suffers through an extreme drought, driven by climate change.

"The forecast for areas around the Caldor fire, in particular, doesn't look that good for the next few days," CNN Meteorologist Michael Guy said. Red flag warnings are in effect for the northern Sierra to western Nevada, including the Lake Tahoe area, until Wednesday night. Strong winds with gusts up to 35 mph are forecast, along with isolated locations getting up to 50 mph, according to the National Weather Service in Reno.

The area is also very dry, with relative humidity running between 5% and 10%, Guy said. The low humidity and lack of rain is providing plenty of parched land for the fire to burn.

Smoke and haze are also going to be a problem and are in the forecast for the next seven days, Guy said, noting this will at least help keep temperatures relatively mild with highs in the upper 70s.

National Forests closed to the public as fires ravage California

There are 13 large fires actively burning in California, scorching a total of 1,460,782 acres, the National Interagency Fire Center reported.

The largest blaze, the Dixie Fire, has been active for 46 days and burned 777,741 acres, according to Cal Fire. It is 48% contained.

Overall this year, 1.76 million acres have burned from 6,913 fires, Cal Fire said.

With resources stretched and no relief from the fire-fueling conditions in sight, the US Forest Service is temporarily closing all national forests in California.

The closure goes into effect Tuesday night and will last through at least September 17, the US Forest Service Pacific Southwest Region said Monday.

The order is a precautionary step to reduce the likelihood that visitors could become trapped during emergency fire circumstances, the Forest Service said.

"We do not take this decision lightly, but this is the best choice for public safety," Regional Forester Jennifer Eberlien said in a statement. "It is especially hard with the approaching Labor Day weekend, when so many people enjoy our national forests."

As the fires continue to spread, approximately 200 US Army Soldiers are being trained to assist firefighters in their battle against the flames, a statement from US Army North Public Affairs said.

Units from Joint Base Lewis-McChord in Washington state will be trained to assist with the response to the Dixie Fire which is burning on National Parks land, the release said.