With a land area nearly the size of Delaware, it is the least densely populated county east of the Mississippi River.

The original county seat was Sageville, now part of Lake Pleasant.

Hamilton County is in the state's north central section, northwest of Albany.

It lies entirely within Adirondack Park and consists mostly of publicly owned parkland.

Research published in 2016 found that Hamilton County had by far the highest suicide rate in the state of New York; at 28 per 100,000 people.

Though the report found instances of suicide to be significantly higher in Upstate generally, the rate in Hamilton County was disproportionate regardless of region; being 22.1, high though still significantly lower, in Lewis County, which was found to have the second highest rate in New York.

[23] Hamilton gave McCain the highest margin of victory in the state.

[24] It was the only county won by Howard Mills over incumbent Chuck Schumer in the 2004 U.S. Senate election.

It also voted for John Faso over Eliot Spitzer for governor in 2006, and for John Spencer 55.5%-42.1% over incumbent Hillary Clinton for the U.S. Senate in 2006, despite Faso and Spencer both losing in landslides statewide.

It was one of only a handful of counties outside Western New York to have voted for Carl Paladino over eventual winner Andrew Cuomo for Governor in 2010.

Democrat Kirsten Gillibrand, however, won the county in her bid to be elected for a full term to the U.S. Senate in 2012.