Using "was" or "were" for proper noun "Northern Plains"

Question

I want to use the phrase "Northern Plains" in a sentence as follows:

"The Northern Plains were a place of great danger; people never went there alone."

Is "were" (plural) the correct form, or do I need to use "was" because the Northern Plains is a single specific place (proper noun)? Or is it just a stylistic choice?

Answer 1

It is a stylistic choice, for example in the Wikipedia article on The "Great Plains", a singular verb is used at first:

The Great Plains [...] is a broad expanse of flatland in North America.

The Great Plains lies across both Central United States and Western Canada

However later, the article switches:

The Great Plains are the westernmost portion of the vast North American Interior Plains

The Great Plains consist of a broad stretch of country...