This is a developing story. Please check back for updates.

UPDATE: 2:18 p.m. EST — The Legion Lake fire grew to more than 2,500 acres, according to KOTA-TV. Some 200 firefighters remained worked to battle the blaze.

The fire had not yet been contained at all and firefighters were expected to stay at the scene for the remainder of the week.

Original story:

A wildfire broke out in Custer State Park in South Dakota Monday and quickly grew to more than 1,600 acres. The park was closed as the fire, dubbed the Legion Lake Fire, continued to spread southeast.

The fire, near Legion Lake Lodge, prompted evacuations in the area, the Rapid City Journal reported. Roads were also closed in the area, including parts of Highway 16A and Highway 87. The flames were headed toward French Creek, KNBN reported. “Fire whirls,” or fire tornados, were reported in the park, according to KNBN.

Firefighters and two large air tankers were deployed to the scene to battle the blaze.

In addition to the Legion Lake Fire, a separate fire was also burning about six miles north of the park, KOTA-TV reported. The Bug Fire consumed about 12.5 acres so far. Initial reports suggested both fires were caused by human actions, though no further details were released.

Winds were expected to reach up to 35 mph as the day went on, the Rapid City Journal reported, citing National Weather Service meteorologist Alzina Foscato. High winds could hinder conditions for firefighters and make containment more difficult.