The Chesapeake Bay impact crater was formed by a bolide that impacted the eastern shore of North America about 35 million years ago, in the late Eocene epoch. It is one of the best-preserved "wet-target" or marine impact craters, and the largest impact crater in the U.S. Continued slumping of sediments over the rubble of the crater have helped shape Chesapeake Bay.
The Transpeninsular Line (at approximately 38° 27' N) is a surveyed line, the eastern half of which forms the north-south border between Delaware and Maryland. The border turns roughly north from the midpoint of the line towards the Twelve-Mile Circle, which forms much of the remainder of the Delaware border.
The so-called Twelve-Mile Circle is not actually a circle but the compound arcs of two or more different circles that have been imperceptibly feathered together to form most of the boundary between the Commonwealth of Pennsylvania and the State of Delaware in the United States. It is nominally a circle with a supposed — yet in fact only approximate and variable — twelve-mile radius, centered in the town of New Castle, Delaware.
The Rachel Carson Greenway is a set of three trails in Central Maryland. When completed, the Rachel Carson Greenway trail corridor will span 25 miles stretching from the historic Adelphi Mill in Prince George's County north to Patuxent River State Park. The largest section of the greenway consists of a network of unimproved hiking trails through the Northwest Branch stream valley gorge in Burnt Mills, Maryland.
Captain John Smith Chesapeake National Historic Trail is a series of water routes in the United States extending approximately 3,000 miles (4,800 km) along the Chesapeake Bay, the nation's largest estuary, and its tributaries in Virginia, Maryland, Delaware, and in the District of Columbia. The historic routes trace the 1607–1609 voyages of Captain John Smith to chart the land and waterways of the Chesapeake.
The Corcoran Environmental Study Area, or the Corcoran Tract, comprises roughly 210 acres (0.85 km) owned by the State of Maryland. Edward S. Corcoran once owned the 110-acre (0.45 km) northwest portion of Corcoran Woods.
The site of the Elkridge Furnace and forge (located in the US state of Maryland), known today as Avalon, was a tract of land patented as "Taylor’s Forest" purchased in 1761 by Caleb Dorsey, an ironmaster. The land was located on the Patapsco river near Elkridge Landing, today being part of the Patapsco Valley State Park. The site first produced pig iron for export to England and after the addition of a forge produced crowbars, some of the earliest tools produced in America.
The List of ridges and summits of the Allegheny Mountains identifies geographic elevations for about 500 miles (800 km) from north central Pennsylvania, through West Virginia and Maryland, to western Virginia in the USA. The range of Allegheny Mountains is part of the Appalachian Mountain range.
The Fairfax Line was a surveyor's line run in 1746 to establish the limits of the "Northern Neck land grant" in colonial Virginia. The land grant, first contrived in 1649, encompassed all lands bounded by the Potomac and Rappahannock Rivers, up to 5,000,000 acres. By 1719, the lands had been inherited by Thomas Fairfax, 6th Lord Fairfax of Cameron (1693-1781). By that time the question of the boundaries of the designated lands had also become highly contentious.
The Star-Spangled Banner National Historic Trail is a National Historic Trail that commemorates the Chesapeake Campaign of the War of 1812. The 290-mile (467 km) trail was named after "The Star-Spangled Banner," the national anthem of the United States. Consisting of water and overland routes, the trail extends from Tangier Island, Virginia, through southern Maryland, the District of Columbia, the Chesapeake Bay, and Baltimore, Maryland.
Bloodsworth Island is an island in the Chesapeake Bay. It lies in southern Dorchester County, Maryland. For much of the 20th century, it was used as a naval gunnery range. Due to extensive contamination by unexploded ordinance, the island is currently off-limits to the public.