Outdoor Play Manager Christopher Hartsfield believes that team sports and physical fitness saved his life. At Concrete Safaris, he has led outdoor play activities and job training for 7 - 24-year-olds, including cycling adventures, fitness circuits and testing, JungleGym - Concrete Safaris' obstacle race and active living fair, and over 35 single-day play events per year since 2014. He earned a B.S in Health & Physical Education from Elizabeth City State University, and has a Wilderness First Aid Certification from SOLO, a Middle Manager Certificate from the American Camp Association, and Outdoor Leadership Training from the Appalachian Mountain Club's Youth Opportunities Program. Prior to joining Concrete Safaris, Christopher 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 is a licensed security and fire brigade officer, and brings a serious commitment to safety. 

Executive Director Mac Levine, MPH, founded Concrete Safaris in 2008 with 16 East Harlem children, growing the organization to serve over 5,000 young people in 2017. She earned a masters in public health from Columbia University’s Mailman School of Public Health in the Built Environment Track, where she won the John and Kathleen Gorman Public Health Humanitarian Award. Mac also graduated cum laude from Northeastern University with a bachelors in music industry and a minor in sociology. Mac is a Senior Fellow at the Environmental Leadership Program and a graduate of the National Outdoor Leadership School. She was recognized in CUNY's 2017 Class of 40 Under 40: The Rising Stars in New York City Food Policy. She has guest lectured at Columbia University, New York University, Icahn School of Medicine at Mount Sinai, and Northeastern University, and presented at the Crime & Food Panel for Icahn School of Medicine at Mount Sinai, the Just Food Conference, and the American Community Gardening Association. She is a member of the Land & Water Conservation Fund Coalition and the No Violence Initiative of the New York County District Attorney's Office. 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.


Garden Manager Ruby Olisemeka is a farmer and farm/garden educator. She has over 10 years of experience teaching garden-based material to children as young as 2 years of age, to seniors over 80 years old. Ruby earned a B.A. in Biology from Lehman College. She frequently lectures on sustainable agriculture and on how to create experential garden, food justice and culturally relevant content for teaching in garden or farm spaces. She has held workshops at NOFA NY; NOFA-CT; City Year Educational Conference; Black Urban Growers Conference; and Just Food Conference. In June 2017, she delivered the opening workshop at Alice Water's Edible Schoolyard Project Academy in Berkeley, where she lead and interactive workshop on incorporating stories and perspectives from indigenous and people of color into garden education. She received her farm training at Stone Barns Center for Agriculture and has spent the last six years building school, communal and community gardens in lower Westchester and NYC. She is passionate about training young and beginning farmers who reflect the diversity of our population; making organic, nutrient dense and sustainablefoods accessible to underserved communities and practising regenerative agriculture.