Hidden Valley Lake is an acid water, shallow trout impoundment located in southwest Virginia at an elevation of approximately 3,600 feet above sea level. Renovation of the dam and outlet structures and fish management procedures are discussed. Subsurface water temperatures and dissolved oxygen values were obtained during the summers of 1965 and 1966. These are discussed in relation to an aeration system installed during the fall of 1965. No definite conclusions concerning beneficial effects on the fishery were arrived at; although dissolved oxygen in bottom waters was higher during the summer in which the aeration system was in operation. The aeration did appear to be effective in removing ice from around the outlet tower. Rainbow trout, Salmo gairdneri, brook trout, Salvelinus fontinalis brown trout, Salmo trutta were introduced into the lake. Brook trout appeared to achieve a better growth rate than either of the other two species. Evidence of reproduction was found only for the brook trout. Creel information indicated the brook trout to be more readily taken than either the rainbow or brown trout, as is shown by the increase in rate of harvest in 1968 when brook trout entered the creel in significant numbers. Trophy size trout were taken occasionally. Rainbow 19-inches in total length and brown trout 21-inches in total length have been reported caught.