The affected area stretches from Tanner Park at the mouth of Parleys Canyon to Sugarhouse Park in Salt Lake City.

Trout Unlimited representative Brock Richardson counted 450 dead Bonneville cutthroat trout in Tanner Park alone this morning after a concerned citizen contacted The Salt Lake Tribune and reported dead fish in the creek. Richardson said he also found dead fish at Sugar House Park, but none below the pond.

"I was up there yesterday and saw them swimming and today they are dead," said Terry Pantuso, who was walking his dog about 9 a.m. this morning when he found the fish. "I passed a woman when I was walking down and she told me there were dead fish everywhere."

DWR employees believe there may have been a release of silt for unknown reasons in the creek in Parleys Canyon above Tanner Park that filled the gills of the fish with dirt. They do not believe there is any cause for human concern, but are not yet sure.

Parleys Creek is not a popular fishery, but it is home to a native population of Bonneville cutthroat trout, which have been proposed, but denied by the courts, for listing as threatened on the endangered species act.