NEMO, S.D. (AP) — Three separate wildfires in the Black Hills of South Dakota have forced evacuations of more than 400 homes northwest of Rapid City and shut down Mount Rushmore, authorities said Monday.

A fire that started near Schroeder Road in the Nemo area, about 15 miles (24 kilometers) northwest of Rapid City, had burned as much as 1 1/2 square miles and was “still moving” on Monday afternoon, according to the Pennington County Sheriff's Office. Several outbuildings and possibly two homes have been destroyed, officials said.

South Dakota Gov. Kristi Noem, who traveled to Rapid City to oversee the response, said the Schroeder Road fire started on private property. She said “there has been losses and that is tragic." No injuries have been reported.

The Sheriff's Department warned earlier that it was a “very active and dangerous scene.” About 250 firefighters were battling the blaze on a windy afternoon when gusts have ranged from around 50 mph to 72 mph, the Rapid City Journal reported.

Two additional blazes were burning southwest of Rapid City, near Keystone, with one covering an estimated 75 acres (30.35 hectares) and the other 20 acres (8.09 hectares). That has caused Mount Rushmore National Memorial to close, as well as surrounding roads.

South Dakota transportation officials shut down Interstate 90 for a 42-mile (68-kilometer) stretch from Kadoka to Murdo due to grass fires. Authorities are asking people to stay away and use alternate routes.