YELLOWSTONE NATIONAL PARK, Wyo. (AP) — The National Park Service has adopted a winter use plan for Yellowstone National Park that focuses on controlling the effects of snowmobiles rather than strictly limiting their numbers.

Park Service Regional Director John Wessels signed the new plan Thursday. Previous winter use plans capped the numbers of snowmobiles and enclosed, multi-passenger snowcoaches allowed in the park each day. That policy will continue for the upcoming winter season, with no more than 318 snowmobiles and 78 snowcoaches allowed in each day.

The new plan to take effect in 2014 focuses on so-called "transportation events," defined as one snowcoach or a group of up to 10 snowmobiles. Up to 110 transportation events will be allowed each day. Yellowstone officials plan to release more detailed rules for winter access in the weeks ahead.