Just a few years ago Jefferson Elementary School in San Diego County, California suffered from low test scores and a lackluster "science from workbooks approach" that was not motivating many in the 75% Hispanic and 50% learning-to-speak-English student body. A partnership program with the San Diego Natural History Museum called Communities Alive in Nature (CAN) changed all that. The program centered on using the watershed, where water drains from mountains to the Pacific Ocean, as a broad canvas where teachers and students could investigate local environmental concerns such as water quality, water conservation, native habitats, and erosion. The heart of the program is Adopt a Watershed, a spiral curriculum that builds on students' learning in each successive grade and includes topics such as water quality, soils, plants, animals, and habitats. This article describes how CAN, a museum-school partnership program, turned an underperforming science program into a distinguished one. Positive results are reflected in students' achievement-test scores in science and other subjects. In fact, since the partnership began in 2001, Jefferson's composite scores have risen steadily from 574 to 750. For Hispanic students, the fastest growing segment of the school population, achievement has increased from 492 to 689. (Contains 1 resource.)