Rapid growth on the South Rim fire in Black Canyon of the Gunnison National Park forced immediate evacuations in Montrose County on Saturday afternoon.

Wildfires have forced evacuations at two U.S. national parks in the West as summer monsoon storms increase lightning in the region.

MONTROSE, Colo. — Black Canyon of the Gunnison National Park in southwestern Colorado is closed due to wildfires, the park said on its website . The fires were caused by lightning strikes Thursday morning, the park said. All visitors and staff were evacuated, and no one will be allowed to enter until further notice.