The pinnacle of the South Island Ultra Series, the 100km race takes participants on an unparalleled adventure through dense rainforests, alongside pristine lakes, and across historic suspension bridges, highlighting the diverse beauty of the West Coast Wilderness Trail with a total elevation gain of 720m. Designed for seasoned ultra-marathoners, this race demands preparation, resilience, and a deep appreciation for nature's grandeur, offering a truly immersive experience in one of the world's most scenic environments. The event's limited entry ensures a unique and personal running experience, fostering a sense of camaraderie among participants as they traverse the trail's challenging yet rewarding terrain. Completing the South Island Ultra 100km is not merely an athletic achievement but a journey through the heart of New Zealand's wilderness, leaving runners with lasting memories of their incredible feat.