Hashing has origins from pre-WWII. But in general it means getting together, running for health, and the excuse to be able to have a pint after the run. There are clubs all over the US and internationally that have meet-ups and events surrounding this. Some sponsored by breweries, some as local clubs. Here are some in the area. They all have slightly different techniques but you'll get the picture…
Run+Beer = Fun
Austin Beer Run Club: Est. 2012Fishtown Beer Runners (Philadelphia)Lehigh Valley Beer Run Club (Bethlehem, PA)Running For Brews (Multiple Locations, FL, CO, TN)