The western national parks managed by the Canadian Parks Service (CPS) are dominated by fire dependent forests of lodgepole pine, spruce and trembling aspen. Values at risk and high-intensity fire regimes limit the acceptability of unscheduled (lightning and unplanned man) ignitions. The potential of using scheduled ignition fires to maintain ecological integrity is being operationally tested. Fire prescriptions often specify relatively intense fire behavior to partially or totally kill forests stands. Depending on the fuel type, this may require head fire rates of spread from 10 to 20 m/min and flame heights of over 5 m. Currently, the CPS is burning approx. 1,500 to 2,500 ha/yr in the Western Region. Aerial ignition is preferred. If stable stand age distributions are to be maintained, long-term objectives would require an average of over 15,000 ha/yr to be burned. However, expansion of the program will be influenced by issues including smoke, risk of fire escape, and evolving objectives for ecosystem management.