A new kind of mountain running race that finishes at the summit of 4,083-foot Mt. Ellen. The winding course includes single-track trails, glades and open slopes, as well as unique natural terrain challenges. Two different race courses include a Single Diamond route gaining more than 1,000 net vertical feet, and a Double Diamond route gaining more than 2,000 vertical feet. For spectators and participants, a weekend-long “BaseCamp” will blend on-site camping, scheduled nature hikes for friends and spectators, training-and-performance exhibits, and a farmer’s market-inspired gathering of local fare. Registration is $120. Limited camping is available. For more information, please visit O2X.com or go to facebook.com/O2Xchallenges