Join the Urban Ecosystem Ecology and Environmental Justice Sections on a exploration of environmental changes along a socioeconomic gradient and learn how the Crosstown Walk can be applied to the courses you teach.  The crosstown walk is a course module that can be used in undergraduate and graduate courses in ecology, design, planning, and social sciences for students to collect ecological and social data to understand the socio-ecological drivers of environmental change in cities. The crosstown walk is particularly useful as a tool that illustrates key concepts about urban ecology and environmental justice. On this field trip, we will introduce the course module and describe how it is used in different types of course. We will  discuss how the module can be used to introduce students to the socioeconomic and demographic drivers of biodiversity in cities, and how the module can be used in a collaborative study of biodiversity in the world's cities. Our three mile walk will be along North Williams St. in Portland, starting and ending in a racially diverse lower middle class neighborhood. The middle portion of the walk goes through an area experiencing rapid gentrification.  We will collect data on temperature, tree canopy cover, birds, insects, and vegetation during the walk. At the conclusion of the walk we will review our findings from the walk and discuss how the module can be used in different courses and settings, and opportunities to participate in a comparison of route data for multiple cities.