[3] The name is modified from a Lenape (Delaware) Native American word meaning "broad bottom lands".

New York's claims were not recognized until the Treaty of Hartford was ratified in 1786 and were not actively asserted until the Holland Purchase.

In 1784, following the peace treaty that ended the American Revolutionary War, the name of Tryon County was changed to Montgomery County in order to honor the general, Richard Montgomery, who had captured several places in Canada and died attempting to capture the city of Quebec, replacing the name of the hated British governor.

In 1789, Ontario County was split off from Montgomery as part of the establishment of the Morris Reserve.

It was sold privately to settlers through the Holland Land Company's office in Batavia, starting in 1801.

[5] Wyoming County is in the western part of New York State, east of Buffalo and slightly west of due south of Rochester.

The land surface is generally broken and hilly, and the soil fertile.

An active geologic fault runs down the Dale valley through Linden, to the east of Batavia and into Lake Ontario.

Movement of the fault is an occasional source of minor earthquakes, which, at most, have toppled a couple chimneys.

The Dale Valley has been developed as a source of salt by way of brine wells, for the chemical industry.

The county is bounded on the southeast by the Genesee River, and drained by tributaries of that stream, as well as Tonawanda, Buffalo, and other creeks.

[6] An important tributary of the Genesee River, Oatka Creek, has its source in the Town of Gainesville within the county.

31.7% were of German, 12.5% English, 10.9% Irish, 10.2% Polish, 9.3% American and 7.7% Italian ancestry according to Census 2000.

In the Senate Special election that same year, the county favored Republican Joe DioGuardi over the Democratic incumbent, Kirsten Gillibrand.

In 2016, Wyoming County once again favored Long as she lost statewide to Schumer.

In 2017 Jon Campbell of the Democrat & Chronicle wrote that the county "is solid Trump Country.