National parks will be free to enter Wednesday in celebration of passage of the Great American Outdoors Act.

Across the National Park System, more than $100 million a year is spent in a bid to control invasive plant and animal species, though the actual cost in lost recreational opportunities is difficult to measure.

It's expected that within two weeks the main Wahweap boat ramp at Lake Powell in Glen Canyon National Recreation Area will close due to falling lake levels, an event that could make it hard or impossible to pull boats out of the lake.

The boundaries of Blackstone River Valley National  Historical Park in Rhode Island and Massachusetts have been finalized. That action marks a significant milestone in the ongoing evolution of a national park that tells the story of the birth of America’s industrialization and its profound impact on society.