The Luquillo Critical Zone Observatory is located in the Luquillo Mountains of northeastern Puerto Rico. The mountain massif drains rapidly to the ocean, and consists of three primary bedrock types: volcaniclastic, granitic, and hornfels. For streams draining the three bedrock types, I will describe the time course of stream chemistry (up to 33 years of data, including major storms and hurricanes); spatial variation in phosphorus; and linkages between longitudinal changes in stream chemistry and bedrock lithology.