(Yellowstone National Park, WY)  --  Authorities say a Portland man is dead after he fell into a scalding hot spring in Yellowstone National Park.  Officials say 23-year-old Collin Nathaniel Scott walked about 225 yards off the boardwalk Tuesday at the Norris Geyser Basin, then slipped and fell into the hot spring.  An attempt was made to recover the body, but Scott's remains couldn't be found.  Park officials say the tragic death must remind all to follow the regulations and stay on boardwalks when visiting Yellowstone's geyser basins.