Goat Island (New York) in the context of Niagara Falls State Park

The Niagara River (/naɪˈæɡərə, -ɡrə/ ny-AGG-ər-ə, -⁠grə) flows north from Lake Erie to Lake Ontario, forming part of the border between Ontario, Canada, to the west, and New York, United States, to the east. The origin of the river's name is debated. Iroquoian scholar Bruce Trigger suggests it is derived from a branch of the local Neutral Confederacy, referred to as the Niagagarega people on several late-17th-century French maps. George R. Stewart posits that it comes from an Iroquois town named Ongniaahra, meaning "point of land cut in two."

The river, occasionally described as a strait, is approximately 58 kilometres (36 mi) long and includes the Niagara Falls. Over the past 12,000 years, the falls have moved roughly 11 kilometres (6.8 mi) upstream from the leading edge of the Niagara Escarpment, creating a gorge below the falls. Today, the diversion of the river for electricity generation has significantly slowed the rate of erosion. The total elevation drop along the river is 99 metres (325 ft). The Niagara Gorge, downstream from the falls, includes the Niagara Whirlpool and additional rapids.

Horseshoe Falls is the largest of the three waterfalls that collectively form Niagara Falls on the Niagara River along the Canada–United States border. Approximately 90% of the Niagara River, after diversions for hydropower generation, flows over Horseshoe Falls. The remaining 10% flows over American Falls and Bridal Veil Falls. It is located between Terrapin Point on Goat Island in the US state of New York, and Table Rock in the Canadian province of Ontario. These falls are also referred to as the Canadian Falls.

Bridal Veil Falls is the smallest of the three waterfalls that make up Niagara Falls. It is located on the United States side in New York state. Luna Island separates it from the American Falls and Goat Island separates it from the Horseshoe Falls. Bridal Veil Falls faces to the northwest and has a crest 56 ft (17 m) wide.

Bridal Veil is similar in appearance to American Falls, starting with a vertical fall of 78 ft (24 m) followed by the water violently descending the talus boulders to the Maid of the Mist pool 103 ft (31 m) below. The total vertical drop is 181 ft (55 m). The crest elevation of the Falls is 508 ft (155 m).