White-tailed deer are magnificent creatures and a common sight across Missouri's landscape. Over the last 100 years, they were brought back from an all-time low of 400 to more than 1.2 million today. They are one of our most valuable species for outdoor recreation, jobs and tourism. The work of keeping our deer herd healthy today is as important as the early work to restore them to the state. Scientists work with hunters and landowners to prevent the spread of disease, especially Chronic Wasting Disease (CWD), which is always fatal. Learn more about deer health, CWD, and mandatory testing in this week's Discover Nature Note.