As shelter-in-place regulations slowly lifted, how could the reopening of public spaces be managed to maintain a high quality visitor experience while adhering to social distancing requirements at that time? For two decades, ExtendSim has been used by the National Park Service to model visitor use in iconic national parks: such as Yosemite, Mount Rainier, Isle Royale, and Rocky Mountain National Parks, Muir Woods National Monument, and the Inyo National Forest. These simulation models have established a basis for visitor use management decision making through examining and simulating relationships between visitor use levels and variables relevant to visitor experience and management operations. The investigation published in Park Science magazine addressing park crowding through scientifically defensible means, a practice now prudent in high-visibility parks and other public spaces.