Wildfires in northwestern Nebraska tripled in size in less than 24 hours, as strong winds pushed flames through the rugged, rural terrain.

More than 285 square miles — an area more than twice the size of the state’s largest city, Omaha — had burned by Sunday afternoon, fire officials said. One of the fires had crossed into South Dakota this weekend and burned more than 50 square miles, including land on the Pine Ridge Indian Reservation.

A day earlier, the fires had only burned roughly 93 square miles in the ranching territory that’s favored by deer and turkey hunters.

“We’ve got a very challenging situation out here because of the winds and the very dry conditions,” Gov. Dave Heineman said Sunday after touring the damage and meeting with officials.