| Valença (Viana do Castelo District) |- | ! scope="row" | | Entrimo (province of Ourense, Galicia) |- | ! scope="row" | | Lerma, Province of Burgos (Castile and León) |} United States The parallel 42° north forms most of the New York–Pennsylvania border, although due to imperfect surveying in 1785–1786, this boundary wanders around on both sides of the true parallel. The area around the parallel in this region is known as the Twin Tiers. The 42nd parallel became agreed upon as the northward limit of the Spanish Empire by the Adams–Onís Treaty of 1819 with the United States, which established the parallel as the border between the Viceroyality of New Spain of the Kingdom of Spain and the western territory of the United States of America from the meridian of the headwaters of the Arkansas River west to the Pacific Ocean. The Treaty of Guadalupe Hidalgo of 1848 then ceded much of what was then northern Mexico to the United States; as a result, the northernmost U.S. states which were created from Mexican territory (California, Nevada, and Utah) have the parallel 42° north as their northern border, and the adjoining U.S. states of Oregon and Idaho have the parallel as their southern border. The parallel passes through the states of Wyoming, Nebraska, Iowa, Illinois, Michigan, Pennsylvania, New York, Connecticut, Rhode Island and Massachusetts, and passes through (or near - within three-tenths degree of latitude) the following cities in the United States: Crescent City, California Yreka, California Hartford, Connecticut Ames, Iowa Chicago, Illinois Kalamazoo, Michigan Coldwater, Michigan Erie, Pennsylvania Jamestown, New York Busti, New York Binghamton, New York Plymouth, Massachusetts Springfield, Massachusetts Worcester, Massachusetts Foxborough, Massachusetts Ashland, Oregon Medford, Oregon Providence, Rhode Island Brookings, Oregon Canada The parallel 42° north passes through the southern end of Lake Michigan and Lake Erie. Part of the water boundary between Canada and the United States passes south of the 42nd parallel. The southern tip of the Canadian province of Ontario just barely goes south of it at Point Pelee and Pelee Island, while the southernmost portion of the Town of Essex at Colchester is located below the 42nd parallel. See also 41st parallel north 43rd parallel north The Twin Tiers region of New York and Pennsylvania The "Jefferson" region of Oregon and California References n42 Borders of Oregon Borders of California Borders of Nevada Borders of Utah Borders of Idaho Borders of