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G-\' Although gravel pits are artificial environments that are typically diked and isolated from the mainstem river. they comprise a.large proportion of pond habitats created by gravel-pit mining in the floodplain in some river corridors along the Upper.Colorado River. Gravel mining operations along the Colorado River in the Grand Valley between Palisade and Lorna, Colorado (15- and 18-mile reaches), between Rifle and Debeque. Colorado, and near Delta. Colorado. on the Gunnison River have created numerous gravel pits that vary in size. depth. shape. and orientation to the mainstem river. During high flow events. some of these ponds have been temporarily connected to the river allowing access to fish. However. these ponds that do not have permanent connections to the river have also trapped fish following recession of high flows. Ponds that are reconnected to the river are less likely to trap endangered fishes. Integrating ponds created from gravel-pit mining into the historic floodplain by removing portions of dikes and re-establishing connectivity to the river may provide off. channel habitats which are essential for effective management of the riverine ecosystem and recovery of endangered fishes. Most researchers believe that connecting isolated ponds to the river can be seasonally beneficial to endangered fishes. Ponds that are gently graded and connected to the river should be evaluated for their possible benefit for.endangered fishes by providing off-channel habitats while reducing or minimizing proliferation of nonnative fishes. Valdez and Wick (1983) and Osmundson and Kaeding (1991) hypothesized that graded gravel pits that flood during runoff and drain with descending flow may benefit adult razorback sucker and Colorado squawfish by providing feeding. resting, conditioning, and possibly spawning areas while minimizing the potential proliferation of nonnative fishes that either compete with or predate upon endangered fishes. Habitat restoration of gravel pits may provide food that should increase survival of larval and juvenile endangered fishes. Graded gravel pits could function as seasonal. surrogate floodplain habitats for use by endangered and other native fishes. Protection, restoration, and enhancement of inundated bottomland habitat along mainstem riparian corridors are believed to be important for recovery of razorback sucker. Before razorback sucker are reintroduced into historical reaches of the Upper Colorado River, reconnecting the river with bottomlands is essential. One site by itself will probablY not be sufficient to establish and maintain self- sustaining populations of endangered fishes. Thus. additional bottomland sites will need to be identified and developed to provide a series or "network" of off. channel habitats. :3