Field stations across the United States provide learning opportunities to the general public through their outreach programming. With approximately 78% and 98% of the US population living within 60 and 120 miles of a field station, respectively, stations have the potential to be key providers of informal STEM education. We surveyed a sample of US biological field stations and asked them to describe their outreach programming and goals. Our findings indicate that field stations prioritize outreach by dedicating personnel and fiscal resources, but such initiatives are highly variable in magnitude and scope. We propose an informal STEM education framework to guide outreach efforts by aligning place-based activities with outreach goals, strands of science learning, and learner engagement theories. Such intentional program design can help stations focus on meaningful learning outcomes for their outreach participants.