The Corner Corner documents, but cannot truly explain, the hobby of visiting locations like:

• Places where three or more states or provinces meet at a point.
• The northernmost, easternmost, southernmost, and westernmost points in states and provinces.
• Other prominent boundary junctions and corners.

For details on any US tri-state, click the boundary junction on the map below.

United States Multi-point Index - Sixty-five locations where 3 or more states meet at a point (includes the District of Columbia.)

Canadian Multi-point Index - Four locations where 3 or more provinces meet at a point, including the Canadian Four Corners.

US/Canada Tri-point Index - Eighteen points where 2 states and a province, or 2 provinces and a state meet.

Extremity Index - The northernmost, easternmost, southernmost, and westernmost points of the states and provinces.

Brian and Gregg Butler's 2001 Expedition - Twenty-nine points and 7700 miles in 18 days.

2000 Holliston Boundary Report - Brian & Joan Butler inspect and mark the bounds.

Tri-State Corners in the United States by Jack Parsell - PDF download (4656KB)