As a city that has lost more than 1/3 of its population over the past 6 decades, some Baltimore neighborhoods suffer from a disproportionate number of vacant and abandoned properties, mired in issues of unclear ownership and “under-water” lien burdens. Cloudy legal and financial restrictions cause properties to cycle through a speculative system that strips them of all equity, and causes them to move out of reach for redevelopment. Evidence suggests that existing processes for addressing these issues, such as tax lien sales and foreclosures, can actually play a role in increasing vacancy rates and amplify neighborhood disinvestment (Dewar, Seymour, and Druță, 2015). Policies aimed at real property tax reform and foreclosure prevention can improve conditions, yet communities, non-profits, and city agencies in Baltimore lacked a unified data system to guide their reform and outreach efforts. One challenge is that property data are housed at various agencies, each using its own system of data storage and dissemination, making it difficult to use different datasets for a single property. The Baltimore City Open Land Data (BOLD) web application arose out of the need to streamline the data gathering process by integrating various datasets for easier use by stakeholders working to stabilize their communities, preserve homeownership, and break the cycle of vacant properties. This presentation will give an overview how BOLD was designed, a short demonstration of the application, and show how it can be used to further research the impact of tax sales and foreclosures in Baltimore City.