The economic and ecological benefits and control costs of western juniper (Juniperus occidentalis Hook) management on rangelands are evaluated using a discrete-time, dynamic economic model developed to depict 4 representative ranches in the John Day region of north-central Oregon. The model's optimization criterion is to maximize the net present value of profits through decisions regarding herd size and composition, cattle sales, and the manipulation of forage production through juniper management practices. Projections are made regarding the impacts of economically optimal juniper management on wildlife populations, stream flows, and erosion levels. Results consistently showed that juniper management options resulted in larger equilibrium herd sizes and greater economic returns. Erosion levels were substantially lower in scenarios that contained juniper management options. Economically optimal juniper management decisions led to increased quail and elk populations, but generally resulted in decreased deer populations. The results indicate there are both economic and ecological benefits from controlling western juniper on Oregon rangelands.