In the heat of summer in 1885, at Fort Abraham Lincoln, on the west bank of the Missouri River, Captain Macauley saw something he had never seen before. The river had spawned millions of mosquitoes and their bites were so bad that Captain Macauley could only remain outdoors if he wore heavy riding boots, “thick trousers, leather gauntlets,” a head-net, and a neckerchief tucked between his hat and shirt-collar.