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Theories persist among aquatic biologists that the damming and impound- ment of the Colorado River and its larger tributaries eliminated the spawn- ing migrations of the squawfish, and was primarily responsible for the drastic decline in numbers of these fish. N.F.R.I. does not believe existing data will entirely support this theory because squawfish have maintained population above fish barriers for several decades without the benefit of an upstream migration. An example of this is the existence of a self-maintaining popu- lation of squawfish in Plateau Creek which is sandwiched between two effective fish barriers on the Colorado River. This population of fish has been separ- ated from downstream migrations since about 1908. Another example is the population of squawfish in the Gunnison River that apparently existed until recent times, at least 1971, according to Paul Holden (1974). The Redlands power dam on the Gunnison is an effective fish barrier most of the time. Ex- ceptions are two annual shutdown periods for maintenance, April 1 and November 1, for a few days each period. During this shutdown period, which may vary from 3-14 days, the dam gates are opened and theoretically fish could move upstream of the dam. This, however, is a time of year when squawfish movement is very limited and for this reason N.F.R.I. considers the Redlands Power Dam to be an effective squawfish barrier. An intensive tagging project would be necessary to confirm the effectiveness of this dam as a barrier. The Redlands Power Dam was originally built around 1900, and squawfish have been documented for at least 70 years above this structure. N.F.R.I. does not feel the dam's function as a barrier to migration is a primary factor in the decline of squaw- fish. Alteration of flow regimes such as have occurred in the Gunnison River must be of some significance in the life history of these fish. Releases from the Curecanti Unit peak in the winter months and are generally at the low point (30)