[cratermoon]

One common definition is west of the 100th meridian, or about halfway through North Dakota. Montana is firmly in the west, as are the other 3 states mentioned, plus Colorado, New Mexico, Arizona, Utah, Nevada, and Washington.

[desert_boi]

Do you have a source pointing at that common definition? I lived a majority of my life in the West US (ID, MT, WA), and have never heard North Dakota referred to as the West.

Maybe it's a Canadian thing? -100W is the border of Manitoba and Alberta?

[msrenee]

I've heard it used for bird ecology for sure. The 100th meridian is the general cutoff between eastern bird species and western bird species. I think it holds true in other areas of biology.

I've driven back and forth across it a lot. Obviously it's a gradient and not some magic barrier the great-tailed grackles cannot cross. And we do get western kingbirds a couple hundred miles east as well as western meadowlarks. It's still a handy boundary so that you know more or less what to expect in a given area ecologically.

https://news.climate.columbia.edu/2018/04/11/the-100th-merid...

https://weather.com/science/environment/news/2018-04-12-100t...

[rascul]

https://www2.census.gov/geo/pdfs/maps-data/maps/reference/us...

[JeremyTerps]

North Dakotan, can confirm, never heard that.

[JeremyTerps]

Lifelong North Dakotan, never heard of or thought of ND being a western state.

[cratermoon]

Where in N. Dakota? I can see that being so for east of Missouri River to the border with Minnesota, but towards the border with Montana the state is decidedly Western in culture and climate.