Walking along the Deschutes River by the Old Mill District, it’s hard to imagine anything else but the area’s clean riparian wildlife, restaurants and recreation activities. It wasn’t always that way. For 79 years, it was a gritty, barren area that was home to an active, working saw mill. It wasn’t until 2010 that residents and visitors could walk into the river from a beach at Riverbend Park. There was even a city law prohibiting floating in the river. “You couldn’t swim in the river,” said Don Horton, Bend Park & Recreation District executive director. “That lasted until the 1980s.” Today, innertubes have replaced cut trees in the river, with…