Montana's Department of Livestock has lifted a requirement that female cattle imported into the state be vaccinated against brucellosis.
Brucellosis can cause pregnant animals to prematurely abort their young.
It's believed to have been eradicated across most of the country except for portions of Idaho, Wyoming and Montana around Yellowstone National Park, where it persists in wildlife.
Two cattle herds in Montana were detected with the disease last year.
State veterinarian Marty Zaluski said Wednesday it was appropriate to lift the vaccination requirement because most of the nation has been declared brucellosis-free by the U.S. Department of Agriculture.
Cattle from states that had brucellosis infections during the past decade still would need vaccinations.
Vaccinations are required in four Yellowstone-area counties in Montana — Beaverhead, Gallatin, Madison and Park.