(DC) (Friends of the National Arboretum) Join us for a 5k run or walk on the idyllic grounds of the National Arboretum and help us raise funds for Arboretum programs. Strollers and dogs are allowed but dogs must stay on a 6′ non-retractable leash. Can’t make it to the National Arboretum but still want to break out your running shoes? ...