A multi-day prescribed burn in Deschutes County jumped containment lines on Thursday, prompting fire agencies to declare a wildfire.The fire on Pine Mountain, about 14 miles southeast of Bend, grew to 2,866 acres by Friday afternoon with the perimeter listed as 25% contained. The fire was mostly burning on federal land, as well as some private land.The wildfire declaration should help the U.S. Forest Service and local fire agencies tap into addi…