White pines reached 250 feet into the sky and six feet in diameter, earning the species the name monarch of the forest. The large white pines here today were only seedlings in 1839, when the Marine Lumber Company cut the first log in the St. Croix Valley. The white pine forests that once grew north of Marine-on-St. Croix, once considered inexhaustible, were gone by 1900, bringing the heyday of lumbering in the St. Croix Valley to an end. White pines can be distinguished from other evergreens by their soft, greenish blue needles in bunches of five and their four- to seven-inch cones.