Born and raised in a single-parent household in North Carolina, Concrete Safaris' Outdoor Play Manager Christopher Hartsfield believes that team sports and physical fitness saved his life. He has led cycling adventures, fitness circuits and testing, and the JungleGym Race Committee since 2014, creating over 35 events per year. He attended Elizabeth City State University, earning a B.S. degree in physical education. He then moved to Brooklyn, where he was a fitness coach and floor trainer at the YMCA Armory in Park Slope instructing 4-18-year-olds in various sports classes and the youth basketball league. He became a security and fire brigade officer at the Barclay Center, and brings a serious commitment to safety. In college, Christopher was a Resident Assistant and Peer Health Educator, overseeing the health and safety of his peers and mentoring middle and high school students. Outside of Concrete Safaris, Christopher enjoys making films and designing apparel. 

Executive Director Mac Levine, MPH, founded Concrete Safaris in 2008 with 16 East Harlem children, growing the organization to serve over 2,800 young people in 2016. She earned a masters in public health from Columbia University‚Äôs Mailman School of Public Health in the Built Environment Track, where she won the John and Kathleen Gorman Public Health Humanitarian Award. Her thesis, "Applications of the California Children's Outdoor Bill of Rights at an East Harlem Public Housing Project," was nominated for a school-wide award. Mac also graduated cum laude from Northeastern University with a bachelors in music industry and a minor in sociology. She is a member of the Executive Leadership Series for Small Agencies at Partnership for After school Education, the Executive Directors' Leadership Circle at The Foundation Center, the Community Walking Trail Planning Committee of the East and Central Harlem District Public Health Office, and The Partnership for a Healthier Manhattan of Icahn School of Medicine at Mount Sinai. Mac is a Senior Fellow at the Environmental Leadership Program, a graduate of the National Outdoor Leadership School, and a Master Composter. She has presented at the Crime & Food Panel for the Healthy Food For Upper Manhattan Workgroup, the 2013 Just Food Conference, and the American Community Gardening Association's 2011 National Conference. She has guest lectured at Columbia University, New York University, Icahn School of Medicine at Mount Sinai, and Northeastern University. She is a co-author of "Closing Health Disparities Through A Multi-Level Approach," published in the International Journal of Child and Human Development as well as in the book Environmental Health Disparities: Costs & Benefits of Breaking the Cycle in 2016. Mac was the first solo female to stand-up paddle (SUP) the Hudson River Water Trail without assistance from Albany to Manhattan in June 2014, and the first person to SUP all five boroughs on the NYC Water Trail in late summer of 2015.