It sounds like one of those crazy word problems from my fifth grade math class: in an urban watershed that is home to one million people, challenged by pollution resulting from more than 18% impervious surfaces, how do you begin to turn 18,000 vacant lots into conservation opportunities? Since our beginnings, Heartland Conservation Alliance has worked with partners to protect nature and places we love in our metro area. Early on, our partnership decided to focus our urban conservation efforts on improving the health and vitality of one of our metro area’s most valuable natural assets, the Blue River. We protect the river by working with landowners and park departments to minimize unsustainable development and reduce the destruction of natural areas in the undeveloped headwaters of the river. Another way we care for the Blue River is to clean up and restore already-developed land in the middle and lower areas of the watershed. In the Middle Blue River Watershed, in our urban core, you can walk down a neighborhood sidewalk and see one house and then two empty lots. Many of those lots are without structures, filled with weeds and trash; some have abandoned buildings. Neighborhoods, city leaders, and nonprofits are working to remove these blighted areas and revitalize communities. We have joined the efforts in hopes to increase ways to connect to nature and in hopes of making the Blue River healthier. In 2014, we dedicated one year actively serving on the Environmental Management Commission's Vacant Task Force and helped create recommendations for using green infrastructure to get abandoned properties back to being productive. In 2015, we brought $60,000 in federal funding to support a two-year study analyzing vacant lots. The two-year project began developing a process to find land best suited for conservation and ecosystem services restoration at the watershed and neighborhood levels. We used existing data to tell us where vacant land was located in the watershed, its proximity to parks, to floodplains, to transportation, and to greenway corridors. We conducted site visits of more than 150 sites and we held several community meetings and interviews to further understand and target properties. We are now exploring how to use these maps to catalyze restoration and conservation. For example, as co-chair of the Green Spaces Vacant to Vibrant Work Group for the Urban Neighborhood Initiative, we are creating tools to help communities restore lots. As ambassador for the Middle Blue River Urban Waters Federal Partnership, we are bringing $250,000 to the city in Marlborough to build a park on a vacant lot at 81st and Troost in partnership with The Conservation Fund’s Parks with Purpose initiative. We recognize that unused land is a costly challenge for our communities, but we are hopeful our work with partners will make a difference in the lives of people, the health of our watershed, and will help us continue to protect and connect to the amazing nature in our metro area.