Fires from Wyoming to Hawaii continue to rage in the National Park System, with thousands of firefighters battling flames that are sending billowing, choking clouds of smoke into some parks and limiting access in others. The Yosemite Valley, Wawona area, and Mariposa Grove of Giant Sequoias all remained closed in Yosemite National Park on Thursday.

In an effort to provide clarity to First Amendment demonstrations and special event permit regulations in Washington, D.C., the National Park Service is seeking public comment on proposed revisions to Title 36 of the Code of Federal Regulations, section 7.96 for the National Mall, President’s Park and other national parks in the Washington, D.C. area. The Park Service says the modifications would maintain opportunities for people to hold special events and exercise their right to demonstrate while outlining clear parameters that protect the iconic landmarks, views and grounds for use and enjoyment of citizens and visitors from around the globe.

Though only about the size of a dime, nonnative shellfish from the other side of the world have infested Lake Powell at Glen Canyon National Recreation Area, where they are impairing beaches, encrusting some boats, and threatening the hydropower operations of the Glen Canyon dam. They also pose a threat to one of the National Park System's top economic drivers.

A plane carrying four visitors from Poland and the pilot was spotted on the flanks of Thunder Mountain in Denali National Park, with all occupants either confirmed or presumed dead, the National Park Service said.