The Northern Tier can refer to
The Northern Tier is a geographic region consisting of five rural counties in north-central Pennsylvania. The Northern Tier is home to roughly 180,000 people distributed among many small towns and the countryside. The region's largest town is Sayre, Pennsylvania on the left-east bank North Branch Susquehanna River and is on Interstate 86 where it dips just south of the Pennsylvania state line). Sayre Yard is a large railyard currently operated by Norfolk Southern that extends across the stateline into Waverly, New York and connects rail transport centers via Wilkes-Barre, Pennsylvania, to freight yards in Philadelphia, Harrisburg, and Baltimore to Buffalo and other Upstate New York cities as well as the Great Lakes basin cities. The Endless Mountains are a major geographic feature. U.S. Route 220, U.S. Route 15 and U.S. Route 6 serve the region.
The Northern Tier also often includes McKean and Potter Counties, the two counties to the west that border New York, though the term Northern Pennsylvania is more commonly used there. The economies, geography and population of these two counties are very similar to that of other Northern Tier counties.
The Northern Tier is the northernmost part of the United States, along the border with Canada (including the border on the Great Lakes).
It can be defined as the states that border Canada (excluding Alaska), but historians include all of New England in the Northern Tier, as well as states of the Pacific Northwest, because of the common culture they shared for more than a century. Sometimes the area was called "Greater New England", because of the influence of its culture as migrants moved west across the continent. It had a consistent political culture until the 1960s. Moving east to west (as the majority of population did), such states include: Connecticut, Massachusetts, Rhode Island, New Hampshire, Maine, Vermont, New York, Ohio, Michigan, Wisconsin, Minnesota, North Dakota, Montana, Idaho, Alaska, and Washington.
The terms Upper Midwest and North Country, New York are related to this term.