Muddy River

The New Zealand mud snail (Potamopyrgus antipodarum) continues to spread in Wyoming, according to this story in the Billings Gazette. Though the prolific snails have been spotted in several western states since the mid-1990s, its appearance in the Bighorn River is its first appearance in Wyoming outside of Yellowstone National Park. Scientists, who are speculating that the snails were introduced via contaminated angling gear, have begun an assessment to determine the extent of the invasion.