while hiking Mount Dana in YNP last month i stopped to cool my feet in a meadow lake and came upon this creature crawling on rock in the water.
he did not move if i lifted my hand out of the water, but continued to crawl on my hand when i placed it back in. he had some feelers and a "proboscis" of sorts.
to me it looked as if his shell/casing was made of pine needles. i tried googling freshwater crustaceans and came up negative.
)