The Idaho Department Lands in a statement on Tuesday says there are now more than 250 ranchers in the region with the training.
The agency told the State Board of Land Commissioners that the number of rangeland fire protection associations has also increased from four to five.
The agency says that ranchers will provide fire protection on 675,000 acres of private rangeland and 2.9 million acres of federal and state rangeland in Gem, Elmore, Owyhee and Twin Falls counties.
Wildfires in recent years have scorched thousands of acres of forage ranchers need to feed livestock.
The agency says that ranchers last year helped federal firefighters on at least 30 wildfires in southern Idaho.