bedrock and scooping out a great basin. The glaciers, and later meltwater, wore away less resistant rock, leaving behind hills and ridges of the harder diabase and anorthosite. At the end of the last glacial period the basin filled with meltwater. The water level fluctuated significantly over time due to blockages of the outlet and post-glacial rebound. The high-water Glacial Lake Duluth deposited clay sediments inland, while later, lower precursors of Lake Superior eroded bluffs and beach terraces. Flora and fauna The park was originally forested with red and white pine. However, these were heavily logged at the beginning of the 20th century, and wildfires sweeping through the cutover land killed many of the remaining saplings and seedlings. Today the vegetation is primarily birch with some spruce, fir, and ash trees. Mammals found in the park include white-tailed deer, moose, black bears, raccoons, snowshoe hares, red foxes, bobcats, and Canadian lynxes. A colony of beavers lives on the Split Rock River. Birds include herring gulls, common loons, and a variety of songbirds. Peregrine falcons nest on the lakeside cliffs. Cultural history Early history Several vestiges of early 20th-century industry are visible in the park. The first white settlement in the Split Rock area was Little Two Harbors, a commercial fishing village populated largely by Norwegian immigrants. The men of the village fished for trout, whitefish, and herring from 16–18 foot skiffs in the fall and winter. Little Two Harbors was inhabited until 1925, although in later years only 4 or 5 residents lived there year-round. Cement foundations of houses and fish processing buildings remain. A logging camp known as Splitrock existed at the mouth of the Split Rock River from 1899 to 1906. Pilings from their dam and wharf are still visible jutting from the water. The Merrill Logging Trail follows the route of their rail line. In 1901 a prospector from Duluth misidentified the outcrops of anorthosite as corundum, an extremely hard mineral valuable as an industrial abrasive. Three years later the North Shore Abrasives Company set up mining operations on Corundum Point, but abandoned the site in 1908 when their product was found to be inadequate. Their crushing house burned down in a forest fire in 1910 but its concrete footings remain. Another remnant from this period is a finely crafted, freestanding stone fireplace atop Day Hill. According to local legend it was the start of a house