Mobile geospatial technologies enable high school students to engage in authentic scientific data collection and analysis that promote spatial-thinking and reasoning skills, as well as problem-solving in a school's local environment. We developed and implemented an Ecological Services investigation aligned to the Next Generation Science Standards in an urban high school with a large population of economically disadvantaged students. The investigation includes local field data collection with mobile devices and classroom data analysis using a freely available Web Geographic Information System or GIS. The field investigation focuses on observation skills and uses a dichotomous key to identify local tree genus and species. Student data analysis focuses on spatial patterns of tree species surrounding the school and exploration of the geospatial relationship between percent tree canopy cover and crime statistics in the city. Students were actively engaged with using geospatial technologies to investigate relevant socio-environmental issues in their community. Students thought critically about the costs and benefits associated with urban trees and proposed changes to their community that will have a positive impact on their local natural and built environment.