“Seventy-five percent of the artificial wetland restoration projects done in America over the past thirty years have failed but when beavers do it, they do it perfectly,” says Stanley Petrowski. He lives in Canyonville, Oregon, a small town in the Klamath Mountains of southern Oregon with a population of 1,660.

Stanley and a neighbour, former logger Leonard Houston, have helped turn the town into the global locus of efforts to restore beavers to their traditional ranges in the wild. They founded the State of the Beaver conference in 2010 after attending a government agency working group where participants spent their time arguing. It’s now in its 13th year.