The Ultra Tour des 4 Massifs is an alpine trail-running series centered near Grenoble, with races that traverse the Chartreuse, Vercors, Belledonne, and Taillefer massifs surrounding the city. It takes place in summer and provides options ranging from shorter mountain trails to full ultra distances, accommodating both runners targeting a single massif and those prepared for a multi-mountain challenge. The longest option connects all four massifs, covering approximately 177 km with nearly 12,000 meters of elevation gain.
The event's design features a modular format, where each massif forms its own loop. Runners can combine these loops to create various distances, including 40, 50, 80, 100, or 180 km. Additionally, stage and relay versions are available, such as a four-day format and a team-of-four ultra, offering more flexibility than many mountain ultras. The race began in 2012, drawing its character from Grenoble, a city situated against the Alps, where the courses depart the urban area to ascend rapidly into rugged mountain terrain.