Full sized map and descriptions of some of the cryptozoological oddities from ‘nessies’ to webbed hominids and a ‘giant eel pig’ at Atlas Obscura.
A 1923 eyewitness account of the monster of Alkali Lake in Nebraska reported that the single-horned alligator-esque creature let out a “dreadful roar” from the water. Described as 40 feet long with a horn like a rhinoceros, as well as an atrocious smell that is near fatal in itself, it’s apparently a very hungry creature and devours anything in its path. Mostly this has been livestock. Sightings peaked in the 1920s, but have since faded, so perhaps Alkali Lake, now called Walgren Lake, is free from its fearsome, smelly unicorn beast.