Travel Going to a national park? Now you need a mask. Here’s what to know about new NPS rule. February 2, 2021February 5, 2021 Morgan Hines, USA TODAY Comments Off on Going to a national park? Now you need a mask. Here’s what to know about new NPS rule. Effective Feb. 2, the National Parks Service requires visitors to wear masks inside buildings and facilities and when distancing isn't possible.