Diverting water from streams for irrigation competes with its use as a recreational fishing resource. This report develops a procedure for estimating the marginal value of water used for fishing that includes the effects of upstream diversions on all points downstream. The downstream effects are dispersed across a wide geographic area and, until now, have not been estimated. The procedure is applied to all 99 major river basins of the contiguous States. The tradeoffs in water allocation are detailed in the 67 river basins where irrigation competes for water with recreational fishing. The results substantiate the role of water for recreational fishing and highlight the implications of a national perspective in water allocation decisions.