Map - Cattaraugus County, New York (Cattaraugus County)

Cattaraugus County (locally known as Catt County) is a county in Western New York, with one side bordering Pennsylvania. As of the United States 2020 census, the population was 77,042. The county seat is Little Valley. The county was created in 1808 and later organized in 1817.

Cattaraugus County comprises the Olean, NY Micropolitan Statistical Area, which is included in the Buffalo-Cheektowaga-Olean, NY Combined Statistical Area. Within its boundaries are the Allegany Indian Reservation of the Seneca Nation of New York, and the Allegany State Park. The Allegheny River runs through the county.

In ancient times, the largely unsettled territory was the traditional homeland of the now-extinct Wenrohronon Indians. It later became the territory of the Seneca people, one of the five Nations of the Haudenosaunee.

During the colonial era, it was claimed by at least three Territories of the United States: New York Colony, Massachusetts Bay Colony, and Pennsylvania Colony, each of which extended their colonial claims to the west until after the Revolutionary War.

When counties were established in the Province of New York in 1683, the territory of Cattaraugus County was included within Albany County. This was an enormous county, including the northern part of New York as well as all of the modern-day state of Vermont and, in theory, extending westward to the Pacific Ocean. As additional areas were settled, the county was reduced on July 3, 1766, by the creation of Cumberland County, and on March 16, 1770, by the creation of Gloucester County, both containing territory now in Vermont.

On March 12, 1772, what was left of Albany County was split into three parts, one remaining under the name Albany County. One of the other pieces, Tryon County, contained the western portion (and thus, since no western boundary was specified, theoretically still extended west to the Pacific). The eastern boundary of Tryon County was approximately five miles west of the present city of Schenectady. The county included the western part of the Adirondack Mountains and the area west of the West Branch of the Delaware River. The area then designated as Tryon County is represented in the 21st century by 37 counties of New York. The county was named for William Tryon, colonial governor of New York.

In the years before 1776, most of the Loyalists in Tryon County fled across the Niagara Frontier into modern day Ontario, Canada. In 1784, following the peace treaty that ended the Revolutionary War (and a treaty with Massachusetts that finally settled who owned Western New York), the name of Tryon County was changed to Montgomery County in honor of the general, Richard Montgomery, who had captured several places in Canada and died attempting to capture the city of Quebec. This replaced the name of the hated British governor.

In practice, however, these counties did not cover modern Cattaraugus County or Western New York. Most of that area lay within the Indian Reserve established in the Treaty of Fort Stanwix by the British; it was intended to be reserved for Native Americans and was ruled off-limits to European settlement.

The newly independent United States sought to extinguish Native reserves after the British ceded their territory east of the Mississippi River and south of the Great Lakes to the United States. This included Iroquois territory in New York; the four nations that had been allies of the British mostly relocated to Ontario, Canada where the Crown gave them land grants in some compensation for losses. The Treaty of Canandaigua, in 1794, extinguished what was left of native title, with the exception of several reservations, three of which were at least partially located in what is now Cattaraugus County.

Ontario County was split from Montgomery County in 1789 as a result of the establishment of the Morris Reserve. In turn, Genesee County was split from Ontario County in 1802 as a result of the Holland Purchase. This period was the beginning of more significant European-American settlement of this western territory. Shortly afterward, Genesee County was reduced in 1806 by the creation of Allegany County.