PRESTON — A year after the idea first emerged, the National Trout Learning Center in Preston is making progress. The center will open in its temporary site May 15 at 120 St. Anthony St. in downtown Preston during the city's Trout Days celebration. When Preston Economic Development Authority director Cathy Enerson began researching ways to bring more people to Preston last year, all the signs pointed toward trout. Cold-water streams in the area support abundant populations of trout, which attract thousands of anglers to the region each year. Recreational angling in the driftless area of southeastern Minnesota, southwestern Wisconsin, northeastern Iowa and northwestern Illinois generates about $1.1 billion annually, according to a study done by Trout Unlimited in 2008. With that in mind, city officials ...