What began as an effort to get signatures in support of a LEGO set to honor the 100th anniversary of the National Park Service, has grown into a National Park Service LEGO Vignettes social media account, with 20,000 followers on Instagram and over 70,000 on Facebook. The mysterious man behind the LEGO curtain, Gavin the LEGO Park Ranger joins Underground History with host Chelsea Rose to talk about this innovative outreach effort.