The Mackyard Ultra started in 2022 when race director Mac McComas was training for his first 100 miler and needed to get a long run in on a hot August weekend in Baltimore. Being a fan of Big's Backyard Ultra, he decided to create a backyard ultra length loop around his neighborhood, use his front porch as an aid station, and invite a couple close friends to join him for accountability to get a slow and steady 50K+ in. After 37ish miles, he was the sole finisher. And so, the Mackyard Ultra was born. The idea proved popular, so the following year he decided to make it an unsanctioned race in Druid Hill Park. From 2023 to 2025, 40-50 runners joined him in the park for 12+ hours of running 4.167 mile loops around the park. With interest and competition growing, he decided to formalize it and bring it to the broader Baltimore running community in 2026.

Now entering its fifth year, the Mackyard Ultra will move from its former home in Druid Hill Park to Shawan Downs. Baltimore City is Mac's home, and Baltimore County is Mac's backyard, where he spends most weekends on trails and power hiking the Oregon Ridge ski slope.