In the project described in this article, urban students from across grade levels, schools, and abilities were brought together by four science teachers to better understand an ecosystem of their local environment, the Boston Harbor. This project comprises two main field experiences to the Boston Harbor: the first one to a nearby beach, and the second to an island in the middle of the harbor. Students came together from four different schools and different neighborhoods across the city of Boston. They consisted of third graders from one school, a mix of fourth and fifth graders from another school, eighth graders from a middle school, and high school students from a school for the deaf and hard of hearing. Although there were different levels of general ecology content understanding across the grade levels, all students were unfamiliar with the ecology of their own environment. Working in mixed-grade groups for the field experiences, students were able to learn side by side with others of different ages, abilities, and backgrounds, while informally rotating roles of encourager, leader, and expert. This project, which was made possible with the help of multiple community partners, greatly enhanced the learning opportunities for students. (Contains 2 figures and 1 resource.)