Six Rivers Land Conservancy started out in 1990 as the Oakland Land Conservancy, which was launched as a committee of the Oakland Parks Foundation. The occasion was part of "Protecting the Natural World," a conference celebrating the 20th anniversary presented by Oakland Parks Foundation at Oakland University. The founding of the Conservancy was inspired by the release of a study in 1988 by Michigan Natural Features Inventory identifying 37 remaining high quality natural areas in Oakland County. The young conservancy became an independent nonprofit organization in 1994. The transition was shepherded by the founding Board of Trustees and guided by Land Trust Alliance Standards and Practices for Land Trusts. Strong partnerships with organizations such as the Land Trust Alliance, Oakland County Planning and Economic Development Services, Oakland County Parks, and Michigan Environmental Council have been a hallmark of the Conservancy since its beginnings.
In late 2007, Macomb Land Conservancy dissolved and combined its membership and service area with Oakland Land Conservancy. Macomb Land Conservancy was founded in 2000 by a group of concerned citizens working along the Coon Creek in Ray Township. The merger of the two organizations was completed in May 2008, creating the Six Rivers Land Conservancy.