45th parallel north

East of Bordeaux, in the municipality of Saint Seurin sur l'Isle, it intersects the Prime Meridian in the corner of an unremarkable field by the side of the A89 highway.

At the border with Uzbekistan it bisects the Aral Sea and its toxic Vozrozhdeniya Island peninsula, site of an abandoned Soviet bioweapons laboratory.

Transecting southern Mongolia it passes through the provinces of Sükhbaatar, Dornogovi (and its capital Sainshand), Dundgovi, Övörkhangai, Bayankhongor, Govi-Altai, and Khovd.

It leaves the Asian mainland on the coast of Primorsky Krai in Russia, north of Vladivostok and continues through the northern part of the Sea of Japan.

It passes through Rishiri-Rebun-Sarobetsu National Park and the adjacent town of Horonobe on the northern tip of Hokkaidō, the northernmost of Japan's main islands, before heading east across the North Pacific Ocean.

Throughout the United States the parallel is marked in many places on highways by a sign proclaiming that the location is halfway between the North Pole and the equator.

[3][4][N 1] The 45th parallel forms some boundaries of or passes through many U.S. states: Oregon, Idaho, Montana, Wyoming, South Dakota, Minnesota, Wisconsin, Michigan, New York, Vermont, New Hampshire and Maine, as well as going through the Canadian provinces of Ontario, Quebec, New Brunswick and Nova Scotia.

Under the Webster–Ashburton Treaty of 1842, original measurement errors stand so that the boundary is not exactly at 45 degrees north but is where the survey monuments were erected in 1772.