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(12-foot high) structure that has been an effective barrier to upstream migration of fishes since its construction in the early 1900's. The Service believed that constructing a fish passage facility would also reestablish endangered fishes to parts of their historic range in the lower 40 miles of the Gunnison River. Additionally, if the target endangered fishes successfully used this prototype passageway, its design might be used in similar situations elsewhere in the upper basin as a part of recovery. As determined from the Windy Gap water depletion formula, funds obtained from these various companies totaled about $400,000. In 1984, a preliminary design proposal was developed that indicated a Denil-type fishway was best suited for this site. The cost for such a structure was estimated to be about $160,000. This proposal, however, did not address some of the critical elements for passing the target fishes. In 1986, the Service contracted the U. S. Army Corps of Engineers to conduct a detailed feasibility study for an experimental fish passage facility at the Redlands Diversion Dam. Nine alternative ladder designs were identified and evaluated, intended to pass adult Colorado squawfish and razorback sucker over the dam. The preferred alternative was a vertical slot with orifice fish passageway. The structure was designed to be flexible to allow for experimental testing of different ladder slopes, attraction flows, and water velocities. The additional experimental features were incorporated into the facility because it was not known whether either of these two fishes would utilize a fishway or under what conditions they would use it. The cost to design and construct the preferred alternative was estimated at $783,000, which was about twice the cost the Service had funds for designing and constructing the passageway at Redlands. Annual operation and maintenance costs were estimated to be about $15,000. After completion, a three-year 4