A coalition of environmental groups, including the National Parks Conservation Association, has sued the Environmental Protection Agency for failing to enforce the Regional Haze Rule required by the Clean Air Act. That failure could lead to "continued release of preventable haze-causing emissions that harm the health of our communities and blur landscapes at our most scenic national parks and wilderness areas," the groups maintain.

As Juneteenth National Independence Day approaches, the National Park Service is marking this holiday at national parks across the Washington, D.C., area.

It’s 10 a.m. on a Saturday and the visitor center at Booker T. Washington National Monument is temporarily closed, albeit for an unusual reason. “The Park Ranger is down in the Historic Area taking care of the animals,” an apologetic sign explains. “They will return soon.”

It's only mid-June, but wildfire conditions are creeping up in some areas of the National Park System, with Voyageurs National Park issuing a ban on wood or charcoal fires and Yellowstone National Park warning visitors of moderate fire danger.