In March 2019, Ancient Forest Exploration & Research (AFER) launched the Peterborough County Old-Growth Forest Project, funded by the Ontario Trillium Foundation. With assistance from our partners, citizen scientists and property owners, we located, mapped, and described ancient forests and other old-growth stands throughout the County. Critical to this effort was the recruitment, training, and collaborative efforts of volunteer citizen scientists. This new approach to the conservation of old-growth forests will eventually be refined and expanded from Peterborough County and applied to the remainder of Ontario's Temperate Forest Region.