YELLOWSTONE NATIONAL PARK, Wyo. — More firefighters headed Tuesday to Yellowstone and Grand Teton national parks, where large, growing wildfires have closed or threaten key roads and forced the evacuation of a large campground during a busy part of the summer tourist season.

The blaze in Grand Teton park made a 5-mile run on Monday, forcing closure of a 10-mile stretch of a US highway that leads into Yellowstone’s South Entrance. More than 4,000 vehicles come and go each day at the site along the main thoroughfare between Jackson and Yellowstone National Park.

The road remained closed Tuesday as firefighters cleared debris and burned trees that might pose a hazard, he said.

The main fire has burned about 10 square miles since it was started by lightning last month.

In neighboring Yellowstone, a fire grew near West Entrance Road. A team of fire managers was being brought in to help, although the fire was not yet being actively suppressed.

All roads and major tourist areas in Yellowstone remained open as firefighters thinned trees and underbrush near the road.

The fire has burned about 42 square miles since it was ignited by lightning on Aug. 8.

Nationwide, other major brushfires are burning in California, Idaho, Montana, Oregon, Utah, Washington, and Wyoming.

In California, a wildfire on the state’s central coast grew to nearly 58 square miles Tuesday. Washington Governor Jay Inslee declared a state of emergency for 20 counties in response to wildfires there.

Associated Press