Adult summer steelhead begin entering the Deschutes River in June and the peak of the run is typically in September. Most of the fish from June to August can be found between the mouth of the Deschutes at river mile 0 to Sherars Falls at river mile 43. As the summer progresses, more and more steelhead pass over Sherars Falls. The peak of the run over Sherars Falls is mid to late September. By October, steelhead are spread throughout the lower 100 miles of the Deschutes.
We have been monitoring summer steelhead populations in the Deschutes River above Sherars Falls since 1977 by conducting a Peterson mark-recapture estimate. We use several monitoring sites to estimate annual wild and hatchery steelhead abundance. The adult salmon and steelhead trap at Sherars Falls is the main component to our monitoring in the Deschutes. We typically tag about two thousand wild and hatchery steelhead from late June to the end of October with an orange Floy (dart) tag. Tagged and non tagged fish are subsequently examined at various trap locations upstream of Sherars Falls for the remainder of the run to estimate annual returns. These additional trap locations include the Round Butte trap at river mile 100, Trout Creek, Shitike Creek, and Warm Springs National Fish Hatchery.
We monitor three components of the steelhead that run in the Deschutes River which includes wild, Round Butte (Deschutes) hatchery stock, and out of basin stray hatchery stock. Hatchery steelhead can be differentiated in the Deschutes by examining their hatchery mark. Round Butte stock hatchery steelhead are uniquely marked with a adipose clip in combination with a maxillary clip. All hatchery marked steelhead observed in the Deschutes without these marks are considered out of basin hatchery strays.
The Deschutes annually gets large numbers of out of basin hatchery strays that originate from hatcheries in the upper Columbia and Snake River basins. We estimate that 50-90% of the total hatchery fish that pass over Sherars falls are out of basin hatchery strays. Many strays are seen as far as Round Butte Dam at river mile 100, where anadromy ends. It is unknown what proportion of out of basin strays stay in the Deschutes and how many drop out and continue their journey up the Columbia.
In addition to using tagged steelhead to estimate abundance, many of the hatchery steelhead we tag at Sherars Falls are captured by anglers in the Deschutes and tributaries of the upper Columbia and Snake Rivers. As a result, many tag numbers are returned to us by anglers and we are able to document movement and locations of the tagged steelhead. If you capture a steelhead with one of these dart tags that say ODFW The Dalles with a number, please notify us by entering the information on the tag return link above, or call (541)296-4628. We will respond to let you know the tag history and associated information with the fish you capture. If you capture a wild summer steelhead in the Deschutes River with an orange dart tag, we ask that you not worry about the tag number and please release it as quickly as possible.