Mountain pine beetle is a devastating forest insect in western North America, where it has killed millions of pines. Changing winter temperatures have allowed the insect to escape geoclimatic barriers to its historic distribution, and it is spreading east through a contiguous band of Canadian jack pine that leads to the northeastern United States. Forest Service scientists and their research partners evaluated the potential suitability of pines common to eastern North America for the insect. Bolts of eastern white, red, and Scots pine were cut from Minnesota and taken to the Black Hills National Forest in South Dakota, where the mountain pine beetle is a native species. Uninfested lodgepole and ponderosa pine, known hosts for the insect, were cut from Wyoming and South Dakota as positive controls. The scientists conducted several studies to determine whether the beetles would recognize the cut bolts as hosts, would reproduce in these species, and would be able to overwinter. All pine species were attractive to mountain pine beetles, were readily colonized, and supported the beetles’ reproduction and development. Host species affected the cold hardiness of overwintering individuals. This research highlights the threat that mountain pine beetle pose to pines of eastern North America.