There are at least 115 named Islands in Montana. These islands occur in rivers, lakes and reservoirs. Islands east of the Continental Divide Missouri River Archers Island, Chouteau County, Montana, , el. Baker Bar, Chouteau County, Montana, , el. Boggs Island , Chouteau County, Montana, , el. Brule Bar, Chouteau County, Montana, , el. Buckshot Island, Cascade County, Montana, , el. Chelsea Island, Roosevelt County, Montana, , el. Council Island, Chouteau County, Montana, , el. Cow Island, Blaine County, Montana, , el. Crow Coulee Bar, Chouteau County, Montana, , el. Duck Island, Valley County, Montana, , el. Evans Bend, Chouteau County, Montana, , el. Fisher Island, Cascade County, Montana, , el. Grand Island, Phillips County, Montana, , el. Holmes Council Islands, Fergus County, Montana, , el. Iron City Islands, Fergus County, Montana, , el. Jones Island, Phillips County, Montana, , el. King Island, Fergus County, Montana, , el. Lower Two Calf Island, Phillips County, Montana, , el. Nelson Island, Cascade County, Montana, , el. PN Island, Fergus County, Montana, , el. Park Island, Cascade County, Montana, , el. Pine Island, Cascade County, Montana, , el. Pablo Island, Chouteau County, Montana, , el. Roosevelt Island, Chouteau County, Montana, , el. Sacajawea Island, Cascade County, Montana, , el. Scout Island, Valley County, Montana, , el. Shonkin Bar, Chouteau County, Montana, , el. Skinners Island, Roosevelt County, Montana, , el. Steamboat Island, Cascade County, Montana, , el. Sturgeon Island, Blaine County, Montana, , el. Taylor Island, Cascade County, Montana, , el. Three Islands, Chouteau County, Montana, , el. Upper Two Calf Island, Phillips County, Montana, , el. White Shield Island, Roosevelt County, Montana, , el. Wolf Island, Chouteau County, Montana, , el. Yorks Islands, Broadwater County, Montana, , el. Yellowstone River Beaver Island, Richland County, Montana, , el. Big Marys Island, Yellowstone County, Montana, , el. Breakneck Island, Richland County, Montana, , el. Buella Island, Richland County, Montana, , el. Cherry Island, Yellowstone County, Montana, , el. Chrome Island, Wibaux County, Montana, , el. Crittenden Island, Richland County, Montana, , el. Devils Island, Richland County, Montana, , el. Diamond Island, Richland County, Montana, , el. Dovers Island, Yellowstone County, Montana, , el. Duck Island, Richland County, Montana, , el. Elk Island, Richland County, Montana, , el. Elms Island, Richland County, Montana, , el. Government Island, Yellowstone County, Montana, , el. Gros Ventre Island, Richland County, Montana, , el. Idiom Island, Richland County, Montana,