Show Low, Ariz. ? Fire crews were finally making progress Wednesday against the worst wildfire in Arizona history, though swirling wind tempered optimism and lightning stirred fear of new fires.

“We have to emphasize that Mother Nature is still in control,” fire spokesman Jim Paxon said. But “we’re on the scoreboard. We haven’t been there for eight days. We’re making some progress.”

The 410,000-acre blaze, one of the most destructive ever in the West, was just 5 percent contained. Officials said they hoped to boost that figure, though it could be several days before they gain the upper hand and that depends largely on the weather.

Smoke has spread across the Southwest and was seen as far south as El Paso, Tex., 260 miles away.

The fire was most active along its northwestern and western flanks. Crews carved and burned a line to keep the blaze from crossing Highway 260. If that happens, flames could spread into 30 to 40 miles of dry timber and threaten hundreds of homes.

In southern Colorado, hot weather and shifting wind challenged firefighters near Durango, where new flames damaged buildings, closed a highway and forced more evacuations. Two fires in the area have burned more than 70,000 acres and destroyed at least 45 homes; thousands have been evacuated.

Southwest of Denver, crews had 77 percent containment of a 137,000-acre fire that has destroyed at least 133 homes.