[3] Garfield County is noteworthy as the site of the discovery and excavation of four of the world's dozen or so major specimens (as of 1994) of Tyrannosaurus rex.

[citation needed] As of the 2010 census, there were 1,206 people, 532 households, and 347 families living in the county.

In terms of ancestry, 33.3% were German, 16.9% were Irish, 15.0% were Norwegian, 13.3% were English, 10.5% were American, 8.1% were Swedish, and 7.4% were Scottish.

It has been the most Republican county in Montana since the 2004 United States presidential election.

[12] In the 2016, 2020, and 2024 elections, Garfield was the only county in Montana to give over 90% of the vote to the Republican nominee, namely Donald Trump.