The Headwaters Group Philanthropic Services, in partnership with Edward W. Wilson Consulting and Coastal Restoration Consultants, Inc., conducted an evaluation of Sustain Our Great Lakes (SOGL) covering the period 2006 through 2011. The research included site visits to 20 selected project sites, a survey of grantees, and interviews with SOGL's partners and informed observers of the program. The evaluation concluded that SOGL's strategic decisions have been sound and strategic and that its grantmaking program has been well executed. Among the grants that are likely to yield the greatest long-term environmental benefits are those supporting the conversion of uplands to wetlands and hydrological modifications to existing wetlands. Of the many weed control projects supported by SOGL, the ones that are most likely to be effective are those that detect and eradicate early stage invasions before they become established. SOGL has also funded a range of connectivity projects that are likely to confer important environmental benefits as long as they are properly maintained and as long as sufficient care is taken to assure that non-native invasive species are not allowed to extend their ranges. By funding relatively labor-intensive habitat restoration projects, SOGL is helping to create jobs and in the longer term is making economic contributions by strengthening sport fisheries, enhancing opportunities for outdoor recreation, and lowering water treatment costs. In some cases, SOGL investments are playing important roles in larger community and economic development efforts. The evaluation offered a series of recommendations aimed at: improving project planning and design, ensuring adequate post-project maintenance, removing barriers to funding complex projects, building knowledge about effective restoration approaches in the Great Lakes region, and helping grantees prepare for the effects of climate change.