SALEM, Ore. (AP) — Six decades after University of California forestry professor Harold Biswell experimented with prescribed burns and was treated with ridicule, he is seen as someone whose ideas could save the U.S. West’s forests and ease wildfire dangers.

Hundreds of millions of acres of forests have become overgrown and prone to wildfires that have devastated towns and blanketed the West Coast in smoke.

Today, officials want to sharply increase prescribed burns. But several realities are stacked against them: The periods between wildfire seasons when prescribed burning can happen safely are shrinking; some forests are too overgrown to ignite without thinning; and prescribed fires can shroud towns in smoke.