Niagara Falls has long been a source of inspiration for explorers, travelers, artists, authors, filmmakers, residents and visitors, few of whom realize that the falls nearly were devoted exclusively to industrial and commercial use. In the 1870s, sightseers had limited access to Niagara Falls and often had to pay merely for a glimpse, and industrialization threatened to carve up Goat Island to power expanding commercial development.

American Falls "shut off" during erosion control efforts in 1969

Other industrial encroachments and lack of public access led to a conservation movement in the U.S. known as Free Niagara, led by such notables as Hudson River school artist Frederic Edwin Church, landscape designer Frederick Law Olmsted, and architect Henry Hobson Richardson. Church approached Lord Dufferin, governor-general of Canada, with a proposal for international discussions on establishment of a public park.

Goat Island was one of the inspirations for the American side of the effort. William Dorsheimer, moved by the scene from the island, brought Olmsted to Buffalo in 1868 to design a city park system and helped promote Olmstead's career. Later, in 1879, the New York state legislature commissioned Olmsted and James T. Gardner to survey the falls and to create the single most important document in the Niagara preservation movement, a Special Report on the preservation of Niagara Falls. The report advocated for State purchase, restoration and preservation through public ownership of the scenic lands surrounding Niagara Falls. Restoring the former beauty of the falls was described in the report as a "sacred obligation to mankind." In 1883, Governor Grover Cleveland drafted legislation authorizing acquisition of lands for a state reservation at Niagara and The Niagara Falls Association, a private citizens group founded in 1882, mounted a massive letter writing campaign and petition drive in support of the park. Professor Charles Eliot Norton and Olmsted were among the leaders of the public campaign, while New York Governor Alonzo Cornell opposed

Preservationists' efforts were rewarded on April 30, 1885, when Governor David B. Hill signed legislation creating the Niagara Reservation, New York’s first state park. New York state began to purchase land from developers, under the charter of the Niagara Reservation State Park. In the same year, the province of Ontario established the Queen Victoria Niagara Falls Park for the same purpose. On the Canadian side, the Niagara Parks Commission governs land usage along the entire course of the Niagara River, from Lake Erie to Lake Ontario.

In 1887, Olmsted and Calvert Vaux issued a supplemental report detailing plans to restore the falls. Their intent was "to restore and conserve the natural surroundings of the Falls of Niagara, rather than to attempt to add anything thereto," and the report anticipated fundamental questions. How would preservationists provide access without destroying the beauty of the falls? How would they restore natural landscapes damaged by man? They planned a park with scenic roadways, paths and a few shelters designed to protect the landscape while allowing large numbers of visitors to enjoy the falls. Commemorative statues, shops, restaurants, and a 1959 glass and metal observation tower were added later. Preservationists continue to strive to strike a balance between Olmsted’s idyllic vision, and the realities of administering a popular scenic attraction. [16]

Preservation efforts continued well into the 20th century. J. Horace McFarland, the Sierra Club, and the Appalachian Mountain Club persuaded the United States Congress in 1906 to enact legislation to preserve the Falls by regulating the waters of Niagara River.[17] The act sought, in cooperation with the Canadian government, to restrict diversion of water, and a treaty resulted in 1909 that limited the total amount of water diverted from the Falls by both nations to 56,000 cubic feet (approx. 1,600 cubic m) per second. That limitation remained in effect until 1950. [18]

Erosion control efforts also have been important. Underwater weirs redirect the most damaging currents, and top of the falls has been strengthened. In June 1969, for example, the Niagara River was entirely diverted from the American Falls for several months through construction of a temporary rock and earth dam (clearly visible in the photo at right).[19] While the Horseshoe Falls absorbed the extra flow, the U.S. Army Corps of Engineers studied the riverbed and mechanically bolted faults which would otherwise have hastened the retreat of the American Falls. A plan to remove the huge mound of talus deposited in 1954 was abandoned owing to cost, and in November 1969, the temporary dam was dynamited, restoring flow to the American Falls. Even after these undertakings, Luna Island, the small piece of land between the main waterfall and the Bridal Veil, remained off limits to the public for years owing to fears that it was unstable and could collapse into the gorge at any time. In order to stop this environmental disaster from happening engineer John Franklin devised plans to halt the falls at night time (this would also help the erosion of the 18th century walkways) yet run all throughout the day. At first the Canadian tourist board opposed at every corner but once assured this would only be done from dusk onwards it was given the go ahead. Work began in March 1997 and was expected to be completed in 2001 but continued until 2003 making it the biggest project to date regarding the environment. 16 mechanical arms are moved by a computer programme to manoeuvre the 1,743 tonnes of steel across the water face and lock into place every evening. [citation needed]

Not far away from the falls, commercial interests have prevailed. Recent construction of several tall buildings (most of them hotels) on the Canadian side resulted in a remarkable alteration and urbanisation of the landscape. It has also caused the airflow over the Falls to change direction.[20] The result is that the viewing areas on the Canadian side are now often obscured by a layer of mist.