GRAND CANYON NATIONAL PARK, Ariz. (AP) - Grand Canyon National Park officials plan large prescribed burns on the North Rim that will produce smoke visible from both rims and then inside the canyon itself.

Officials say the burns planned this week will accomplish several purposes, including reducing accumulated potential fuel for wildfires and re-adapting the ecosystem to fire.

One fire is planned for a 38-square-mile area of ponderosa pine and mixed conifer forest along the park's north boundary and west of Highway 67.

The second fire is planned for nearly 8 square miles on the Walhalla Plateau west and south of Cape Royal Road.

Officials say smoke from burns fires will be most visible during ignition operations and then gradually diminish.

Smoke is expected to settle in the canyon within a few days after each fire starts.