The Maid of the Mist II (Years of service: 1956–83) is well known for its role in the July 9, 1960, rescue of Roger Woodward, a seven-year old boy who became the first person to survive a plunge over the Horseshoe Falls with nothing but a life jacket. The boat was retired from service in 1983 and relocated to the Amazon River, where it served as a missionary ship for years after.

The Ontario Power Company hydro-electric generating plant also opened in 1905. This American based company built its generating plant at the base of the Horseshoe Falls just above river level.

Water enters this generating station from an inlet located one mile upstream of the Falls near Dufferin Islands and is brought to the plant through buried conduit pipes and steel penstocks tunneled through the rock. The conduits, two steel and one wooden bound with iron hoops and encased in cement run underground 6,180 feet (1884m) to the top of the generating station. There each conduit connects with six penstocks six feet in diameter. At the point where the conduits and the penstocks join, there is a section which turns upwards into a spillway called a surge tank.

The surge tanks serve to reduce fluctuations in head and pressure during both the increase and decrease of loads. The spillways being open and provided with overflow pipes send any excess water to the river when the load is suddenly reduced and this prevents any dangerous rise in pressure. Only one of these surge tanks exist today located south of the Victoria Park Restaurant. The illumination battery is located on top of it.

The fifteen generators produced 203,000 horsepower (132,500 kilowatts) of 25 cycle electric power. This plant has twice been flooded by ice and water in 1909 and 1938 putting it out of service each time for many months. In December 1999, the Ontario Power Generation Company (formerly Ontario Hydro) decommissioned the Ontario Power Station from service. This was done to accommodate the building of the permanent Casino Niagara on the former transformer building site overlooking Queen Victoria Park. According to the Ontario Power Generation Company, this power station has been mothballed and its future status will be reviewed from time to time.