Book excerpt: What is Sasquatch? Thousands of people believe in it. Hundreds say they have seen it. But the mystery of Sasquatch has not been solved . . . Sasquatch, also known as Bigfoot, is a cryptid—a creature of cryptozoology. Cryptozoology is the study of creatures not recognized by traditional science, and it is the quest to understand things that cannot be proven via ordinary channels. Kelly Milner Halls interviews cryptozoologists, linguistics experts, anthropologists, biologists, and regular people like us who have seen, heard, or maybe stumbled across evidence leading them to believe that Sasquatch is real. Serious Sasquatch seekers are as skeptical as unbelievers. They are not out to collect great stories. They are out to put together facts. The difference is, they are willing to keep an open mind. Do you believe in Sasquatch?