Dunes 50K Ultra & Heavy Half

The Dunes 50K Ultra & Heavy Half is an endurance event scheduled for Saturday, April 25, 2026, at Jonathan Dickinson State Park in Hobe Sound, Florida. This race is widely recognized for its high level of difficulty due to the terrain of the Atlantic Coastal Ridge. Runners navigate through 16 distinct natural communities across more than 11,000 acres, including prairie wetlands and the infamous "Dunes of Heaven and Hell." The defining challenge of this course is the deep, rolling sugar sand, which significantly increases the physical demand compared to traditional hard-packed trails.

Jonathan Dickinson State Park is located in Martin County, Florida. Geographically, the park is home to the Loxahatchee River, Florida’s first federally designated "Wild and Scenic River." The environment is a mix of pine flatwoods, mangrove swamps, and cypress sloughs. In late April, coastal Florida typically experiences high humidity and temperatures; average daytime highs reach 28°C (82°F) while lows stay around 19°C (66°F). The intense sun exposure on the dunes and the heat index are major factors that runners must manage throughout the morning.

The event is known for its high level of organization and limited field size to preserve the park's natural trails and maintain the quality of the runner experience. Registration includes specific runner swag and is managed through the UltraSignup platform, with a final closing date on the day of the race. The organizers enforce a strict policy of no refunds and no transfers, though vouchers were honored for earlier registration windows. In addition to the adult distances, the event hosts a free Kids Fun Run to engage local families and promote youth trail running. The finish line provides a celebration for participants who have completed what is considered one of the most grueling trail challenges in the state.