The Henvey Inlet wind project, which will be built in the Parry Sound district of Ontario, will be owned 50:50 by Pattern and Henvey Inlet First Nation's Nigig Power Corporation.
A power purchase agreement has been struck with the Ontario Power Authority, which will see it buy the energy from the project over a 20-year period.
Pattern claims that this will be the largest project on Canadian First Nation land. It represents the company's eighth wind project in the country.
The developer expects to arrange financing for the development in 2016, with construction set to start later that year.
Pattern also has the right of first offer for the project, should Nigig Power choose to sell its stake.