2,4-D; 2,4,5-T, and a mixture of these two chemicals were tested for effectiveness in lowering the live crown and increasing the basal sprouting of browse grown beyond the reach of elk and deer. Concentrations of 3/4, 1 1/2, and 3 lb acid equivalent per acre were applied by helicopter in late June. Date of spraying was studied separately. The mixture at 3 lb per acre was most effective in killing aerial crowns. Rocky Mountain maple (Acer glabrum) was relatively resistant to these sprays; Scouler willow (Salix scouleriana), Saskatoon serviceberry (Amelanchier alnifolia), creambush rockspirea (Holodiscus discolor), and bitter cherry (Prunus emarginata) were moderately sensitive; redstem ceanothus (Ceanothus sanguineus), and Lewis mockorange (Philadelphus lewisii) were very sensitive. Willow sprouted prolifically; rockspirea and maple sprouted moderately; ceanothus and mockorange sprouted poorly. Species differed considerably in reaction to date of spraying. Early summer and late summer spraying were usually more effective than midsummer spraying; however, the study revealed no seasonal pattern that could be used as a general guide for spraying to achieve optimum effectiveness in browse rehabilitation. Limitations governing present use of these herbicides for browse improvement in northern Idaho should be noted carefully. Only cautious use of spraying is proposed.