This paper describes a novel use of traffic simulation software to model and manage recreational river use. River tourism usually benefits the local economy, but the influx of visitors can also burden the other functions of a river such as agricultural irrigation and critical habitat for flora and fauna. The management of boats on a river is very similar to the management of cars on a freeway. This paper describes how these similarities were modeled with the software package VISSIM. The paper elaborates on the differences encountered, including a discussion about the underlying differences between a traffic engineer's concept of capacity and that of a recreational manager. The model was used to evaluate three management strategies for dealing with future growth: (a) do nothing, (b) build and improve boat ramps, and (c) issue limited boat launch reservations. The three strategies were evaluated on the basis of density (boats per mile) and boat ramp delay (excess minutes because of queuing). The input for the model included nearly 600 boats and 1,200 visitors. The results suggest that lower density and delay are best achieved by issuing limited reservations. The paper is intended for managers of public lands who may not be familiar with traffic simulation software. The approach could be extended to the management of other recreation facilities, such as bike paths and hiking trails. The paper is also useful for traffic engineers interested in new perspectives on capacity and congestion.