States Ranked by Straight Line Borders

West Virginia has no straight borders at all: 0% of its perimeter is a surveyed line. The WV Encyclopedia documents the breakdown as 52% rivers, 31% ridge crests, and 17% lat/long lines — but those lat/long segments are not straight surveyed lines drawn by Congress; they follow watershed logic and local agreement. Every practical mile of its boundary follows the Ohio River (northwest), Big Sandy and Tug Fork rivers (east, with Kentucky), the Potomac River (northeast, with Maryland), or Allegheny ridge crests (southeast). Its jagged shape, often compared to a turkey foot, is entirely the product of physical geography.

Texas ranks 47th despite its reputation as a large, boxy state. The Rio Grande runs roughly 1,254 miles along the Mexican border. The Red River runs approximately 640 miles along the Oklahoma border. The Sabine River defines most of the Louisiana border. Only the borders with New Mexico and the Oklahoma panhandle are straight lines, totaling about 17% of the full perimeter. Michigan ranks 48th because the Great Lakes define nearly its entire boundary; the only straight segment is the short Indiana-Ohio land border in the south.

Congress passed the Land Ordinance of 1785, establishing the Public Land Survey System, a rectangular grid of north-south meridians and east-west parallels that would be used to partition all federal territory west of the Ohio River. Every state created from that territory afterward had its borders drawn on this grid, regardless of rivers, ridges, or any physical feature on the ground.

Colorado has four borders, all perfectly straight: the 37th and 41st parallels (south and north) and the 102nd and 109th meridians (east and west). The only break is a fraction of a percent where the Colorado River grazes the southwestern corner near the Four Corners monument. Wyoming's borders are equally rigid: four surveyed lines with no natural feature serving as a legal boundary anywhere along the full perimeter.

Kansas, New Mexico, and Utah are similar, all exceeding 93% straight. The practical effect was that western borders were drawn on paper before settlers arrived, with no existing rivers or colonial boundaries to negotiate. The result is visible from any satellite image: the West looks like a grid, the East does not.

Missouri's borders are 73% river: the Mississippi along the east and southeast, the Missouri River along the north and west, and the Des Moines River at the northeast corner. Its only straight segment is the southern border with Arkansas along the 36°30' parallel, about 27% of the total perimeter. Iowa has a near-identical profile: straight only on the north and south parallels, with the Mississippi on the east and the Missouri plus Big Sioux on the west.

Texas combines all three natural types. The Red River defines its northern border with Oklahoma, running approximately 640 miles. The Sabine River defines most of its eastern border with Louisiana. The Rio Grande defines the entire southern and southwestern border with Mexico, roughly 1,254 miles of river border. Only the borders with New Mexico and the Oklahoma panhandle use straight lines. Texas is 83% natural despite its reputation as a large, boxy state — that mental image comes from its straight panhandle top, which is only a small fraction of the full perimeter.

Illinois ranks 41st at just 25% straight. The Mississippi River forms the entire western border, roughly 590 miles. The Ohio River defines the southern tip. The Wabash River forms part of the Indiana border. Only the Wisconsin border in the north and a portion of the Indiana border in the east are surveyed straight lines.

Kentucky's eastern border with Virginia and West Virginia follows Appalachian ridge crests for about 30% of its perimeter. Tennessee's eastern border with North Carolina runs along the same chain for 25%. North Carolina's western border is defined by the Blue Ridge and Great Smoky Mountain divide. These ridge borders predate formal surveys; colonial-era governors agreed the watershed was the line because it was the most visible feature on the landscape.

Montana and Idaho share the Continental Divide along part of their mutual border. Idaho's eastern border follows the divide and the Snake River in alternating sections, producing a 20% mountain share. Montana's western border runs through the Bitterroot Range for about 15% of its perimeter. Alaska's border with Canada follows the 141st meridian on the east, then traces a coastal mountain arc in the southeast panhandle.

Pennsylvania ranks 8th most geometric despite being a colonial-era eastern state. The Mason-Dixon line on the south, surveyed by Charles Mason and Jeremiah Dixon between 1763 and 1767, is one of the most precisely executed surveys in American history. The western border with Ohio follows the 80°31' meridian. The northern border with New York was surveyed in the 1780s. Only the Delaware River on the east (~140 miles) and Lake Erie on the northwest (~40 miles) introduce natural segments into an otherwise rectangular state.

Connecticut ranks 16th at 68% straight, higher than most people expect for a colonial New England state. Its three land borders with Massachusetts, Rhode Island, and New York were all established by colonial surveys in the 17th and 18th centuries and drawn as straight lines. Long Island Sound coastline on the south accounts for the remaining 32%. Massachusetts has an identical profile: three straight land borders and Atlantic coastline.

Texas ranks 47th, one of the most naturally bordered states in the country, despite the common image of a boxy state. Most of the outline that looks like a box — the panhandle top and the New Mexico line on the west — is only about 17% of the actual perimeter. The rest is three major rivers: the Red River, Sabine River, and Rio Grande, plus Gulf coastline.