Grand Canyon, Ariz. – Grand Canyon fire managers are making plans to initiate the Walla Valley Prescribed Fire (Walla Valley Rx) within the next few weeks on the North Rim of Grand Canyon National Park.
The Walla Valley Rx will be located in the Walla Valley and Point Sublime area, approximately ten miles west of the North Rim developed area. The fire will be bounded on the west side by the w6 road and the canyon rim, on the south and east sides by the canyon rim, and on the north and northeast sides by the w4 road.
The Walla Valley burn unit consists primarily of ponderosa pine. About three-quarters of the burn unit last burned in 2001. Approximately 5,300 acres will be burned.
In an effort to simulate natural fire events in the North Rim forests, the Walla Valley Rx will use a point source ignition technique intended to mimic a group of lightning ignitions. A total of six ignition points will be ignited by helicopter in groups of two. The ignition points will be allowed to burn in all directions in the same way naturally ignited fires would burn. The fire is expected to burn over a period of weeks, exposing it to a variety of weather and wind conditions. As a result, it is
expected that the effects of the Walla Valley Rx will more closely resemble a natural fire than the effects seen on most conventional prescribed burns.
Point source ignition will occur only after blacklining along the w6, w4 and Point Sublime roads has been completed, creating a boundary free of burnable vegetation to the northwest, north and northeast.
Prescribed fires play an important role in decreasing risks to life, resources, and property by reducing accumulations of forest fuels and maintaining the natural role of fire in a fire-adapted ecosystem. Like all prescribed fires, the plans for the Walla Valley Rx contain a set of parameters which define (among other things) the expected weather and fuel conditions under which the fire can be initiated. Prior to implementing the burn, fire managers will evaluate current conditions and will only
ignite the fire if all of the prescribed conditions are within those parameters.
In order to assure fire fighter and visitor safety, Point Sublime and the w4 road south of its junction with the Swamp Point Road will be closed during the Walla Valley Rx. Swamp Point, Fire Point and the w1 road are expected to remain open.
It is expected that smoke from the Walla Valley Rx will be visible from most of the South Rim, as well as from Highway 67 and the entrance station on the North Rim. Low to moderate smoke impacts are possible on Highway 67 and in the North Rim developed area. Visitors should also expect smoke to settle into the canyon in the evenings and to rise out again once
temperatures warm during the day. Coordination with the Arizona Department of Environmental Quality is ongoing.
For additional information on the Walla Valley Rx, please contact Grand Canyon Public Affairs Specialist Shannan Marcak at 928-638-7958, or visit the park’s fire information page at www.nps.gov/grca/parkmgmt/fire_info.htm