This paper is about the design and quantitative analysis of distributed approaches for optical flow switching (using dynamic lightpath setup) in a wide area WDM backbone network. The major contribution of this work is to design realistic integrated approaches for flow routing, wavelength assignment, and connection setup in a truly distributed setting, and assess the relative performance of these on a nationwide wide area network (WAN) backbone. A simulation model is used which models timing, wavelength, and fiber constraints. Results are presented in terms of backbone utilization for a given blocking probability of optical flows.