Before trapping nearly exterminated the beaver their dams may have submerged 234,000 square miles of the country, an area comparable in size to the combined area of Nevada and Arizona. The removal of beaver was so complete that even Aldo's son, the eminent hydrologist Luna Leopold, failed to realize the role beavers once played in river systems in the West and across the nation. Combining historical records, trapping accounts and First Nations oral history revealed the once nearly universal presence of beaver in California. Recent work by Lanman and others (2012, 2013) has completely revised the story. For example, in California the biologists believed that beavers were historically relatively rare and found in few areas. By the time biologists and other scientists started studying ecosystems they were so degraded they offered little information about how they functioned before the beaver were removed in the 1700s or 1800s.

His book also highlights the 'shifting baselines' problem often faced by ecologists and environmental historians. In most cases Beaver Deceivers can keep water flowing freely despite the beavers ingrained need to build dams and conserve water. He offers a clear eyed view of the great benefits beaver dams can provide, and also reviews the many solutions that have been developed to minimize unwanted blocking of culverts and flooding caused by beaver dams. His profiles of the 'beaver believers' and their successes (and sometimes failures) will help get more people out watching, supporting, and enjoying these furry ecological engineers. He makes it clear enough for the general reader, but detailed enough for a professional ecologist.

Goldfarb provides a remarkable look into the effect beavers have on critical issues for America, drought relief, flood control, fisheries, and biodiversity. It should be required reading for every ecology and history student, land managers, ranchers, fishermen, developers and birdwatcher in America! This book rises to the level of George Perkins Marsh's Man and Nature (1864), Aldo Leopold's Sand County Almanac (1948), Rachel Carson's, Silent Spring (1962), and Andrea Wulf's The Invention of Nature (2016). Ben Goldfarb's new book about beavers challenges us all to better understand what we have lost and what we can gain with the help of the industrious beaver. Every once in a while a book arrives that delivers a new and powerful environmental message.

Eager the secret life of beavers