Latitude & Longitude Boundaries of Iowa

Iowa's geographic boundaries are defined by parallels and meridians, giving it a near-rectangular shape (distorted by river borders):

• Latitude: 40° 36′ N (southern border, MO) to 43° 30′ N (northern border, MN).
  Note: Source gave 41°39′–43°30′; 40°36′ is the legal southern boundary (Sullivan Line).
• Longitude: 90° 8′ W (eastern border, Mississippi River) to 96° 31′ W (western border, Big Sioux River).
  Note: Source gave 90°16′–96°38′; legal boundaries follow river centerlines.

Key Geographic Points

• Centroid: ~42.0° N, 93.5° W (near Story City).
• Extreme Points:
  • North: Northwood (43°30′N)
  • South: Keokuk vicinity (40°36′N)
  • East: Mississippi River at Dubuque/Keokuk
  • West: Big Sioux River at Sioux City

Iowa spans ~200 miles N-S x 310 miles E-W. Land area: 56,272 sq mi (26th).