A project called Mobile City Science (MCS), a partnership between the University of Washington, New York Hall of Science, the Digital Youth Network, and two high schools, leverages young people's proclivity for on-the-move digital engagement to re-place and mobilize learning through public, community settings that youth identify as being relevant to their daily lives. At its most fundamental level, MCS teaches and engages young people in new forms of data science, especially around collecting and interpreting spatial, real-time, and dynamic data. This digital STEAM curriculum has more ambitious objectives. Ultimately, the research team hopes this work disrupts an absence of youth input in neighborhood and community development processes, using the power of spatial data and visualizations that young people create about their communities as a ticket for entry into ongoing policy and planning conversations. As youth will be the ones making critical decisions about these same communities in due time, it is prudent to apprentice them into valued forms of civic participation. Moreover, as long as youth ideas go unheard, leaders and adult community stakeholders have an incomplete picture -- and are missing potentially transformative solutions -- regarding current issues. This example of a digital STEAM curriculum for youth to engage in data science with mobile technologies provides ideas for teachers to make instruction more public-facing.