Ever slipped on slimy river stones? Blame rock snot — High Country News

Ever slipped on slimy #river stones? Blame rock snot, an #algae that's smothering streambeds: http://t.co/YYrAwdpzWA pic.twitter.com/oBLCQ3ctJl

— High Country News (@highcountrynews) March 18, 2015