As part of their Watershed Function Scientific Focus Area (SFA), Berkeley Lab and its collaborating institutions (e.g., USGS) have established a "Community Watershed" in the headwaters of the East River near Crested Butte, Colorado (USA), designed to quantify processes impacting the ability of mountainous systems to retain and release water, nutrients, carbon, and metals. The ongoing research spans a range of scales from hillslope to catchment to basin, with surface water and groundwater linking multiple geomorphic compartments. A major goal of this SFA research is to generate a transferable understanding of mountain hillslope to river dissolved nutrient, carbon, and metals transport, integrating extensive and novel field observations with fully coupled numerical models. The mountain headwater Oh-Be-Joyful Creek is part of the East River SFA located approximately 6 km northwest of the town of Crested Butte and is a key tributary of the Slate River. The creek is generally incised into bedrock (predominantly Mancos Shale) and many steeper sections have little to no bed sediment. Banks range from bedrock walls to avalanche and rock slide deposits. At an elevation of approximately 2900 m A.S.L., the regional Peeler fault intersects Oh-Be-Joyful Creek from the south creating a preferential groundwater discharge zone. This data release presents various water quality data collected along the Oh-be-joyful Creek from the main channel, groundwater discharge points, and small tributaries, including data collected during a constant rate dye injection near the Peeler fault zone.