WARM SPRINGS, Ore. (AP) — The Warm Springs Reservation has become the first government in Oregon to require quarantine and masks under certain circumstances amid the coronavirus pandemic. The Tribal Council this week ordered any citizen or tribal employee working on the reservation to self-isolate if a healthcare professional says they should.

The move comes after a spike in positive COVID-19 tests on the reservation, where citizens were also told to wear face masks in public if they can’t maintain 6 feet of distance, Oregon Public Broadcasting reported.

The tribes’ approach to slowing the spread of disease is more drastic than in nearby counties under state authority.

In neighboring Jefferson County, officials are drafting plans to be among the first places in the state to ease restrictions, beginning May 15.

Warm Springs government buildings will stay closed until at least June 1. The reservation’s main source of revenue, Indian Head Casino, also remains closed.

The reservation is home to approximately 4,000 people, many of whom are connected to Jefferson, Wasco and Deschutes counties through work, family, shopping and school.

There were 11 confirmed positive cases of COVID-19 on the reservation as of May 4, tribal authorities said.