|



|
| Click on the above photo for a live cam. |
The Big Sioux River,
located in eastern South Dakota, and NW Iowa, is 390 miles long, starting
from its source in Roberts County S.D. , a mile and one half north and half mile west of Summit. The river was first mapped by French explorers in 1688, but detailed, accurate
mapping did not occur until the great astronomer and cartographer, Joseph Nicolett, along with his assistant, the famed John C. Fremont, mapped the area in detail in 1839. The book by Martha Bray, Joseph Nicollet and His Map. 1994, has details of Nicolette's adventure and copies of his famous maps.
The river starts
one mile and a half north of Summit S.D. at an elevation of 2020 feet at Latitude 45 degrees
19' 22.8" North and Longitude 97 degrees 2' 30" West. The location is a half-mile East of Interstate 29, 75 miles east
of Aberdeen, SD. It is the
NW1/4 of section 28, Summit township.
The river provides drainage for the east side of the Coteau in South
Dakota.
| Click on the map to go to google maps |

|
| Source of the Big Sioux |
| Confluence of the Big Sioux and Missouri Rivers |

|
| The Big Sioux ends its journey at the Missouri River at Sioux City, Iowa |
| Big Sioux running into the muddy Missoluri |

|

|
| Source of the Big Sioux looking west toward I29 |
| Confluence of the Big Sioux and Missouri Rivers |

|
| Looking west, the Big Sioux is closest, the Missouri behind. |
| Click on the photo for large map. |
|
|
| The Big Sioux as shown on Nicollet's 1839 map |
|