The composition of noble gases in both gas and water samples collected from Horseshoe Spring, Yellowstone National Park, was found to be depth dependent. The deeper the sample collection within the spring, the greater the enrichment in Kr, Xe, radiogenic 4He, and 40Ar and the greater the depletion in Ne relative to 36Ar. The compositional variations are consistent with multi-component mixing. The dominant component consists of dissolved atmospheric gases acquired by the pool at the surface in contact with air. This component is mixed in varying degree with two other components, one each for gas and water entering the bottom of the pool. The two bottom components are not in equilibrium. In Horseshoe Spring, the bubbles entering at the bottom strip the atmospheric-derived pool gases from the surrounding water while en route to the surface. If the original bottom bubbles are noble gas poor, as in the case of Horseshoe, the acquired pool gases can then quickly obliterate the original bubble composition. These results are used to demonstrate that Yellowstone spring surface gas samples, and perhaps similarly sampled thermal springs from other hydrothermal systems, have gas abundances that depend more on spring morphology than processes occurring deeper in the hydrothermal system.