KENDRICK MOUNTAIN WILDERNESS, Ariz. – The Boundary Fire grew to 450 acres Wednesday morning as crews worked to protect homes and a historic cabin in the area.

Division Group Supervisor Chad Rice said the flames, started by lightning June 1, were burning in the same area scorched by the Pumpkin Fire in 2000, leaving less timber to burn.

“Significantly less fuel than the 2000 fire, but there’s still quite a bit of dead and down that needs to be cleaned up,” Rice said.

The hills and dead and downed trees made it unsafe for fire crews to fight the flames directly. Another challenge was that nothing motorized CAN be used in the wilderness, so firefighters counted on road systems -- burning around them to make a strong perimeter.

“Using those features creates significantly less work for the firefighters on the ground where we can be more efficient,” Rice said.

This indirect attack also helped protect the 18 homes Coconino National Forest staff said were occupied in the area.

Coconino National Forest spokesperson Kaitlyn Webb said those structures weren’t in imminent danger Wednesday.

“There’s no threat to those structures as of now, and they are just being taken into account as a value at risk and something that we are mitigating by putting in those contingency lines,” Webb said.

But the lines aren't protecting a lookout tower and historic cabin.

“Since that is the top of the mountain and fire moves uphill, it is going to steadily grow that direction,” Webb said.

A hand crew was helicoptered up there Wednesday afternoon to wrap the structures in fire-resistant material and clear vegetation around them.

Rice said it was likely the Boundary Fire would grow to 17,000 acres and expected to have it contained in two to four weeks.