“Option value” provides theoretical justification for conserving wildlife species lacking known value, but empirical assessments of actual realizations are rare. We examine quasi-option value in the context of gray wolf eradication, which aimed to protect humans and their property historically, but also reduced the potential for wolves to improve human well-being today. We estimate the effects of long-run differences in the presence of wolves north, but not south, of Canada’s Saint Lawrence River on animal-related (primarily deer) vehicle collisions. Wolves reduce the share of animal collisions by 38 percent, reducing risk to human life and property.