Allegany County is a county in the Southern Tier of the U.S. state of New York. As of the 2020 census, the population was 46,456. Its county seat is Belmont. Its name derives from a Lenape word, applied by European-American settlers of Western New York State to a trail that followed the Allegheny River; they also named the county after this. The county is bisected by the Genesee River, flowing north to its mouth on Lake Ontario. During the mid-nineteenth century, the Genesee Valley Canal was built to link southern markets to the Great Lakes and Mohawk River. The county was also served by railroads, which soon superseded the canals in their capacity for carrying freight. Part of the Oil Springs Reservation, controlled by the Seneca Nation, is located in the county.

Buffalo is the second-largest city in the U.S. state of New York and the seat of Erie County. It is located in the eastern end of Lake Erie, adjacent to the Canadian border with Southern Ontario, and is at the head of the Niagara River. With a population of 278,348 according to the 2020 census, Buffalo is the 76th-largest city in the United States. The city and nearby Niagara Falls share the two-county Buffalo–Niagara Falls Metropolitan Statistical Area (MSA). The MSA had an estimated population of 1.1 million in 2020, making it the 49th largest MSA in the United States. The Western New York region containing Buffalo is the largest population and economic center between Boston, Massachusetts and Cleveland, Ohio. Before French exploration, the region was inhabited by nomadic Paleo-Indians, and later, the Neutral, Erie, and Iroquois nations. In the 18th century, Iroquois land surrounding Buffalo Creek was ceded through the Holland Land Purchase, and a small village was established at its headwaters. Buffalo was selected as the terminus of the Erie Canal in 1825 after improving its harbor, which led to its incorporation in 1832. The canal stimulated its growth as the primary inland port between the Great Lakes and the Atlantic Ocean. Transshipment made Buffalo the world's largest grain port. After railroads superseded the canal's importance, the city became the largest railway hub after Chicago. Buffalo transitioned to manufacturing during the mid-19th century, later dominated by steel production. Deindustrialization and the opening of the St. Lawrence Seaway saw the city's economy decline, diversifying to service industries such as health care, retail, tourism, logistics, and education while retaining some manufacturing. The gross domestic product of the Buffalo–Niagara Falls MSA was $53 billion in 2019. The city's cultural icons include the oldest urban parks system in the United States, the Albright–Knox Art Gallery, the Buffalo Philharmonic Orchestra, Shea's Performing Arts Center, the Buffalo Museum of Science, and several annual festivals. Its educational institutions include the University at Buffalo, Buffalo State College, Canisius College, D'Youville College and Medaille College. Buffalo is also known for its winter weather, Buffalo wings, and two major-league sports teams: the National Football League's Buffalo Bills and the National Hockey League's Buffalo Sabres.

Cattaraugus 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.

Rochester () is a city in the U.S. state of New York, the seat of Monroe County, and the fourth-most populous in the state after New York City, Buffalo, and Yonkers with a population of 211,328 in 2020. The city of Rochester forms the core of a larger metropolitan area with a population of 1 million people, across six counties. The city was one of the United States' first boomtowns, initially due to the fertile Genesee River Valley, which gave rise to numerous flour mills, and then as a manufacturing center, which spurred further rapid population growth.Rochester rose to prominence as the birthplace and home of some of America's most iconic companies, in particular Eastman Kodak, Xerox, and Bausch & Lomb (along with Wegmans, Gannett, Paychex, Western Union, French's, Constellation Brands, Ragú, and others), by which the region became a global center for science, technology, and research and development. This status has been aided by the presence of several internationally renowned universities (notably the University of Rochester and Rochester Institute of Technology) and their research programs; these schools, along with many other smaller colleges, have played an increasingly large role in Greater Rochester's economy. Rochester has also played a key part in US history as a hub for certain important social/political movements, especially abolitionism and the women's rights movement.Today, Rochester's economy is defined by technology and education (aided by a highly educated workforce, research institutions, and other strengths born in its past). While the city experienced some significant population loss as a result of deindustrialization, strong growth in the education and healthcare sectors boosted by elite universities and the slower decline of bedrock companies such as Eastman Kodak and Xerox (as opposed to the rapid fall of heavy industry with steel companies in Buffalo and Pittsburgh) resulted in a much less severe contraction than in most Rust Belt metro areas. The Rochester metropolitan area is the third-largest regional economy in New York, after the New York City metropolitan area and the Buffalo-Niagara Falls Metropolitan Area. Rochester's gross metropolitan product is US$50.6 billion—above those of Albany and Syracuse, but below that of Buffalo.Rochester is also known for its culture, in particular its music culture; institutions such as the Eastman School of Music (considered to be one of the most prestigious conservatories in the world) and the Rochester International Jazz Festival anchor a vibrant music industry, ranked as one of the top-10 music scenes in the US in terms of the concentration of musicians and music-related business. It is the site of multiple major festivals every year (such as the Lilac Festival, the aforementioned Jazz Festival, the Rochester Fringe Festival, and others that draw hundreds of thousands of attendees each) and is home to several world-famous museums such as The Strong National Museum of Play and the George Eastman Museum, the oldest photography collection in the world and one of the largest.The Rochester metro is ranked highly in terms of livability and quality of life and is often considered to be one of the best places in America for families due to low cost of living, highly ranked public schools and a low unemployment rate. A great divide, though, exists between its inner-city component (which has at times had the highest child poverty rate in the nation) and its affluent, well-educated southern suburbs. It is considered to be a global city, ranked by the Globalization and World Cities Research Network as having sufficiency status.