Category Events - United States, Sioux Falls (SD) Calling all free spirits. You're invited to our 115th Anniversary Spring Open House. 2018 is the biggest launch in Harley history. 9 totally reinvented Softail models powered by the Milwaukee-Eight engine. 3 new custom touring bikes. All the lastest accessories. And more. Bring a friend and join us for our 115th Anniversary Spring Open house. More info to come!