The text: 'Gambel oak is frequently found as a highly competitive understory species in southwestern ponderosa pine stands. When the pine is removed, either by harvesting or wildfires, this sprouting oak species flourishes, making pine reestablishments very difficult. Prescribed fires were conducted in the spring, summer, and fall on a ponderosa pine-Gambel oak site to test the potential for oak control at various times of the year. The fires were applied when oak phenoloy suggested periods of low root carbohydrates, theoretically reducing the sprouting potential. One-half of the plots were burned only once, while the rest were burned a second time, 2 years later. One burn generally resulted in large (100-150 percent) oak-density and (10-40 percent) frequency increases, and only temporary cover decreases. A second burn in either the spring or fall failed to reduce the large number of oak sprouts. In contract, a second mid-summer burn resulted in reduction of 20 percent density, 16 percent frequency, and 12 percent cover. Sprouting potential is still apparent after two burns, but trends indicate that frequent, midsummer fire application may eventually lead to some measure of oak control. This should reduce the competitive status of the oak, favoring pine growth and natural pine regeneration.'