Thirteen dams, twelve deflectors, and several covers were constructed in a 450-yard section of Hayes Brook, Prince Edward Island, to create suitable hiding places for brook trout, Salvelinus fontinalis (Mitchill). In the following year the standing crop of fingerlings (age 0) was above average. The numbers of age I and older trout were approximately doubled. The alterations had no noticeable effect on the growth of trout.