The Columbia Slough in Portland, Oregon, often gets a bad rap. It's been called a "swamp," an "open sewer," even the "slough of despond." But clean-up efforts in recent years have begun to rehabilitate the slough's reputation and restore its value as a thin ribbon of connectivity for migrating birds and year-round wildlife. In their environmental memoir, This Rough Magic: At Home on the Columbia Slough, Nancy Henry and Bruce Campbell...