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razorback suckers. From 1979 through the late 1980s, I-70 was constructed through DeBeque <br />Canyon (CDOT, 1975). In this process the Colorado River was moved, narrowed, channelized, <br />and another major spawning area, the Colorado River Overflow, was lost. Mr. Kidd observed <br />that by 1985, all of the important razorback spawning areas in this reach had been disturbed or <br />removed, and razorback populations had plummeted. <br />Through the early 1980s, razorback suckers were relatively common in the Grand Valley and in <br />the 15-mile reach. In 1983 and 1984 extreme flood water levels in the Colorado River resulted <br />in destruction of three more important spawning areas, the Walter Walker Wildlife Area lake, the <br />Palisade Labor Camp slough and the 32 1/2 Road pond. The 32 1/2 road pond has been partially <br />restored though most of the agricultural tail water remains rerouted directly into the river. These <br />areas remain essentially non-functional for the endangered fish. Mr. Kidd considers the alteration <br />and loss of the critical spawning and rearing habitat, beginning in the 1970s, to be the most <br />important factor in the decline of the razorback sucker over the past 20 years. In the past, <br />periodic severe flooding events probably created new backwater areas at the same time older <br />backwaters were being filled. Now, however, the reduced volume of flow in the river, and bank <br />protection have decreased the creation of new backwaters, while filling of the older ones continues <br />to take place. The result is the almost complete elimination of prime spawning areas. <br />Concurrent with the loss of spawning and rearing areas, non-native fish, including gambusia, <br />green sunfish, largemouth bass, crappie, catfish, and carp, have proliferated and have come to <br />dominate all remaining backwater areas. Many ponds were purposefully converted to non-native <br />game species. Prior to 1975, the non-native fish populations had not yet reached the critical levels <br />which seem to have precluded successful regeneration of most endemic fish. <br />9CM\REP0R7SIBAWPP-C.WWE 10