The Fifth Principal Meridian starts from the old mouth of the Arkansas River

Arkansas River

The Arkansas River is a major tributary of the Mississippi River. The Arkansas generally flows to the east and southeast as it traverses the U.S. states of Colorado, Kansas, Oklahoma, and Arkansas. The river's initial basin starts in the Western United States in Colorado, specifically the Arkansas...

, and, with the base line running west from the old mouth of the St. Francis River

St. Francis River

The Saint Francis River is a tributary of the Mississippi River, about long, in southeastern Missouri and northeastern Arkansas in the United States...

, governs the surveys in Arkansas

Arkansas

Arkansas is a state located in the southern region of the United States. Its name is an Algonquian name of the Quapaw Indians. Arkansas shares borders with six states , and its eastern border is largely defined by the Mississippi River...

, Missouri

Missouri

Missouri is a US state located in the Midwestern United States, bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. With a 2010 population of 5,988,927, Missouri is the 18th most populous state in the nation and the fifth most populous in the Midwest. It...

, Iowa

Iowa

Iowa is a state located in the Midwestern United States, an area often referred to as the "American Heartland". It derives its name from the Ioway people, one of the many American Indian tribes that occupied the state at the time of European exploration. Iowa was a part of the French colony of New...

, North Dakota

North Dakota

North Dakota is a state located in the Midwestern region of the United States of America, along the Canadian border. The state is bordered by Canada to the north, Minnesota to the east, South Dakota to the south and Montana to the west. North Dakota is the 19th-largest state by area in the U.S....

; those in Minnesota

Minnesota

Minnesota is a U.S. state located in the Midwestern United States. The twelfth largest state of the U.S., it is the twenty-first most populous, with 5.3 million residents. Minnesota was carved out of the eastern half of the Minnesota Territory and admitted to the Union as the thirty-second state...

, west of the Mississippi River

Mississippi River

The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

 and west of the third guide meridian north of the river; and in South Dakota

South Dakota

South Dakota is a state located in the Midwestern region of the United States. It is named after the Lakota and Dakota Sioux American Indian tribes. Once a part of Dakota Territory, South Dakota became a state on November 2, 1889. The state has an area of and an estimated population of just over...

 all east of the Missouri River

Missouri River

The Missouri River flows through the central United States, and is a tributary of the Mississippi River. It is the longest river in North America and drains the third largest area, though only the thirteenth largest by discharge. The Missouri's watershed encompasses most of the American Great...

, and the surveys on the west side of the river to a limiting line following the third guide meridian (of the Sixth Principal Meridian

Sixth Principal Meridian

The Sixth Principal Meridian extends from the base line coincident with the north boundary of Kansas in latitude 40°N south through the state to its south boundary in latitude 37°N and north through Nebraska to the Missouri River and governs the surveys in Kansas and Nebraska; the surveys in...

 system), White River

White River (Arkansas)

The White River is a 722-mile long river that flows through the U.S. states of Arkansas and Missouri.-Course:The source of the White River is in the Boston Mountains of northwest Arkansas, in the Ozark-St. Francis National Forest southeast of Fayetteville...

, and the west and north boundaries of the Lower Brule Indian Reservation

Lower Brule Indian Reservation

The Lower Brulé Indian Reservation is an Indian reservation that belongs to the Lower Brulé Lakota Tribe. It is located on the west bank of the Missouri River in central South Dakota in the United States. It is adjacent to the Crow Creek Indian Reservation...

. This meridian is nearly coincident with 91° 03' 42" longitude west from Greenwich.

This was the first Meridian of the new Louisiana Purchase and covered about 2000000 acres (8,093.7 km²). Eventually it would cover all or most of six states. There was much discussion regarding where the base line would be with the primary spot being and extension of the third PM baseline. Ultimately it was decided to use the confluence of the St Francis River and the Mississippi River for the base line and the confluence of the Arkansas and Mississippi for the Meridian. Two survey teams started on the same day and proceed North and West respectively. The initial point became the place where this lines crossed. This is one of many examples where the Meridian line and base line determined the initial point rather than the other way around. As a result the initial point is in the middle of a high water swamp. The site today consists of a 900 feet (274.3 m) boardwalk from a parking lot into the swamp. Not only is this spot well preserved it is an excellent opportunity to see the interior of a swamp.

At the terminus of the boardwalk there is a granite monument. The monument reads "This stone marks the base established Nov. 10, 1815 from which the lands of the Louisiana Purchase were surveyed by United State Engineers, the first survey from this point was made to satisfy the claims of the soldiers of the War of 1812, with land bounties.
Erected by the Arkansas Daughters of the American Revolution.
Sponsored by the L'Anguille Chapter"

The Davidson Family of Marvell, Arkansas made this land available, a portion of their farm, this the park and monument.