Lake Agassiz was a large proglacial lake that existed in central North America during late Pleistocene, fed by meltwater from the retreating Laurentide Ice Sheet at the end of the last glacial period. At its peak, the lake's area was larger than all of the modern Great Lakes combined.
The St. Croix River is a tributary of the Mississippi River, approximately 169 miles (272 km) long, in the U.S. states of Wisconsin and Minnesota. The lower 125 miles (201 km) of the river form the border between Wisconsin and Minnesota. The river is a National Scenic Riverway under the protection of the National Park Service. A hydroelectric plant at the Saint Croix Falls Dam supplies power to the Minneapolis–St. Paul metropolitan area.
The Laurentide Ice Sheet was a massive sheet of ice that covered millions of square miles, including most of Canada and a large portion of the Northern United States, multiple times during the Quaternary glacial epochs, from 2.58 million years ago to the present.
Lake Pepin is a naturally occurring lake on the Mississippi River on the border between the U.S. states of Minnesota and Wisconsin. It is located in a valley carved by the outflow of an enormous glacial lake at the end of the last Ice Age. The lake formed when the Mississippi, a successor to the glacial river, was partially dammed by a delta from a tributary stream and spread out across the ancient valley.
Savanna Portage State Park is a state park of Minnesota, USA, established in 1961 to preserve the historic Savanna Portage, a difficult 6-mile (9.7 km) trail connecting the watersheds of the Mississippi River and Lake Superior. The portage trail crosses a drainage divide separating the West Savanna River, which drains to the Mississippi River and the Gulf of Mexico, from the East Savanna River, which flows in an opposite direction to the Saint Louis River, Lake Superior and the Great Lakes, and the Saint Lawrence River to the Atlantic Ocean.
Superior National Forest, part of the United States National Forest system, is located in the Arrowhead Region of the state of Minnesota between the Canada–United States border and the north shore of Lake Superior. The area is part of the greater Boundary Waters region along the border of Minnesota and the Canadian province of Ontario, a historic and important thoroughfare in the fur trading and exploring days of New France and British North America.
Interstate Park comprises two adjacent state parks on the Minnesota–Wisconsin border, both named Interstate State Park. They straddle the Dalles of the St. Croix River, a deep basalt gorge with glacial potholes and other rock formations. The Wisconsin park is 1,330 acres (538 ha) and the Minnesota park is 298 acres (121 ha). The towns of Taylors Falls, Minnesota and St. Croix Falls, Wisconsin are adjacent to the park. Interstate Park is within the Saint Croix National Scenic Riverway and the Ice Age National Scientific Reserve. The western terminus of the Ice Age National Scenic Trail is on the Wisconsin side. On the Minnesota side, two areas contain National Park Service rustic style buildings and structures that are listed on the National Register of Historic Places.
Jay Cooke State Park is a state park of Minnesota, United States, protecting the lower reaches of the Saint Louis River. The park is located about 10 miles (16 km) southwest of Duluth and is one of the ten most visited state parks in Minnesota. The western half of the park contains part of a rocky, 13-mile (21 km) gorge. This was a major barrier to Native Americans and early Europeans traveling by canoe, which they bypassed with the challenging Grand Portage of the St. Louis River. The river was a vital link connecting the Mississippi waterways to the west with the Great Lakes to the east.
Lake Duluth was a proglacial lake that formed in the Lake Superior drainage basin as the Laurentide Ice Sheet retreated. The oldest existing shorelines were formed after retreat from the Greatlakean advance, sometime around 11,000 years B.P. Lake Duluth formed at the western end of the Lake Superior basin. Lake Duluth overflowed south through outlets in Minnesota and Wisconsin at an elevation of around 331 m above sea level.
Lake Minong was a proglacial lake that formed in the Lake Superior basin during the Wisconsin glaciation around 10,000 B.P. This was the last glacial advance that entered Michigan and covered only part of the upper peninsula. Lake Minong occurred in the eastern corner of the Lake Superior basin while Lake Duluth was in the western end. The lakes became separated when the glacier reached the upper peninsula. Lake Minong expanded to the north as the ice retreated after 9,800 B.P. When the ice retreated from the Keweenaw Peninsula, Lake Duluth merged into Lake Minong.
The geology of Minnesota comprises the rock, minerals, and soils of the U.S. state of Minnesota, including their formation, development, distribution, and condition.
The U.S. State of Minnesota is the northernmost state outside Alaska; its isolated Northwest Angle in Lake of the Woods is the only part of the 48 contiguous states lying north of the 49th parallel north. Minnesota is in the U.S. region known as the Upper Midwest in interior North America. The state shares a Lake Superior water border with Michigan and Wisconsin on the northeast; the remainder of the eastern border is with Wisconsin. Iowa is to the south, South Dakota and North Dakota are to the west, and the Canadian provinces of Manitoba and Ontario are to the north. With 87,014 square miles (225,370 km2), or approximately 2.26% of the United States, Minnesota is the 12th largest state.
The glacial history of Minnesota is most defined since the onset of the last glacial period, which ended some 10,000 years ago. Within the last million years, most of the Midwestern United States and much of Canada were covered at one time or another with an ice sheet. This continental glacier had a profound effect on the surface features of the area over which it moved. Vast quantities of rock and soil were scraped from the glacial centers to its margins by slowly moving ice and redeposited as drift or till. Much of this drift was dumped into old preglacial river valleys, while some of it was heaped into belts of hills at the margin of the glacier. The chief result of glaciation has been the modification of the preglacial topography by the deposition of drift over the countryside. However, continental glaciers possess great power of erosion and may actually modify the preglacial land surface by scouring and abrading rather than by the deposition of the drift.
The Duluth Complex, the related Beaver Bay Complex, and the associated North Shore Volcanic Group are rock formations which comprise much of the basement bedrock of the northeastern part of the U.S. state of Minnesota in central North America. The Duluth and Beaver Bay complexes are intrusive rocks formed about 1.1 billion years ago during the Midcontinent Rift; these adjoin and are interspersed with the extrusive rocks of the North Shore Volcanic Group produced during that same geologic event. These formations are part of the Superior Upland physiographic region of the United States, which is associated with the Laurentian Upland of the Canadian Shield, the core of the North American Craton.
The Traverse Gap is an ancient river channel occupied by Lake Traverse, Big Stone Lake and the valley connecting them at Browns Valley, Minnesota. It is located on the border of the U.S. states of Minnesota and South Dakota. Traverse Gap has an unusual distinction for a valley: it is crossed by a continental divide, and in some floods water has flowed across that divide from one drainage basin to the other. Before the Anglo-American Convention of 1818 it marked the border between British territory in the north and U.S. – or earlier, French – territory in the south.
Glacial River Warren, also known as River Warren, was a prehistoric river that drained Lake Agassiz in central North America between about 13,500 and 10,650 BP calibrated years ago. A part of the uppermost portion of the former river channel was designated a National Natural Landmark in 1966.
The River Warren Falls was a massive waterfall on the glacial River Warren initially located in present-day Saint Paul, Minnesota, United States. The waterfall was 2700 feet (823 m) across and 175 feet (53 m) high.
The East Savanna River is a small yet historic stream in Aitkin and Saint Louis counties in the U.S. state of Minnesota. With a total length of 15.3 miles (24.6 km), the river rises in Wolf Lake, a small body of water within a spruce bog in Savanna Portage State Park, and flows northeasterly to the Saint Louis River at Floodwood, whence its waters flow to Lake Superior through the Great Lakes and the Saint Lawrence River to the Atlantic Ocean. A few thousand years ago the East Savanna was part of the Mississippi River itself, originating in northeast Minnesota and flowing southwesterly to Big Sandy Lake, from which the great river drained down its present valley to the Gulf of Mexico.
The North Shore Highlands are a physiographic and ecological region of the U.S. state of Minnesota in central North America. They were formed by a variety of geologic processes, but are principally composed of rock created by magma and lava from a rift about 1.1 billion years ago, which rock formations are interspersed with and overlain by glacial deposits. Their ecology derives from these origins, with thin, rocky soils supporting flora and fauna typical of their northern, inland location.
Lake Jordan was a glacial lake formed during the late Pleistocene along the Jordan River. After the Laurentide Ice Sheet retreated, water melting off the glacier accumulated between the Rocky Mountains and the ice sheet. The lake drained along the front of the ice sheet, eastward towards the Yellowstone River and Glacial Lake Glendive.
