A female mountain lion that has been studied since she was just a few weeks old has been killed in an apparent collision with a vehicle, according to staff at Santa Monica Mountains National Recreation Area in California.

Different road surfaces -- asphalt, concrete, gravel -- create different sounds when traffic passes over them. And that's why Death Valley National Park staff will be listening carefully in the coming months to decide which surface best to use when roads need resurfacing.

University of Arkansas researchers are using laser imaging to create a highly accurate, three-dimensional, digital map of public trails inside Carlsbad Cavern, the namesake cave of Carlsbad Caverns National Park, New Mexico.

While National Park Service air quality analysts don't think an oil refinery proposed near Theodore Roosevelt National Park would pose a problem under normal operating conditions, they are concerned that visibility could be impacted by "upset conditions" and want North Dakota officials to do additional review of the company's permit application.