Not talking about the Four Corners (NM, CO, UT and AZ) but the geographical four corners of the lower 48 – Florida Keys, Pacific Northwest, Southern California and Northeast Maine — or about as close as one can get.
Certainly one can drive north on US 5 into Canada from Washington state or into Canada from Maine on I-95, but that is hardly adventurous. While a drive down to Key West can be an adventure, if you know where to stop along the way (future blog post)! Anyways, here is how I checked off the four geographic corners (not the most extreme 4 corners but pretty darn close):
Southeast: Cape Sable, Florida 25° 16′ 19.87″ N, 81° 7′ 25.1″ W see blog post
Southwest: San Diego (walked across the US-Mex Border land bridge to Tijuana, Mexico) 32°32’33.4″N 117°01’42.6″W
Northwest: PNW, ferry to Victoria BC. from Seattle 48°22’05.9″N 123°10’06.9″W
Northeast: Northern Maine fishing trip 45°33’27.2″N 69°45’15.1″W
Bonus locations: North American Pole of inaccessibility (South Dakota) and continental divide (Colorado, WY and Montana).
Have you been to any or all four geographic corners, please leave comments!