CHEYENNE, Wyo. (AP) — The state of Wyoming wants to ensure those who live and work in Yellowstone register their vehicles in the state.

The Wyoming Department of Transportation, at the request of Gov. Matt Mead and members of Wyoming's congressional delegation, is pushing to get more Yellowstone residents and workers to follow state law and purchase Wyoming registrations and driver's licenses.

State and federal officials say they don't know how many of the about 550 permanent and more than 3,000 seasonal employees working for the National Park Service and Yellowstone's concessionaire, Xanterra Parks & Resorts need to get Wyoming plates. But with an average vehicle registration costing a couple hundred dollars, the state could theoretically be losing out on hundreds of thousands of dollars in fees each year.