Mount Rainier National Park is the most recent unit of the National Park System to announce that you'll need a reservation to enter the most popular areas of the park during the busy summer months. At the same time, Shenandoah National Park has announced that a pilot program it's been running for two years for access to Old Rag will be permanent going forward.

Reservation systems to get into national parks are controversial. Many folks argue they hinder spontaneity in travel, others like the assurance of knowing they can get into a national park such as Arches, or Rocky Mountain, or Glacier, at a specific time on a specific day. To explore the issue of reservations systems in the parks, we're joined today by Cassidy Jones, the senior visitation manager for the National Parks Conservation Association who keeps an eye on these programs, how they're operating, and whether they make a difference.