My friend and I were hiking in the Boulder Canyon area. We reached the summit of Battleship Mountain. From there we descended down into LaBarge Creek and started boulder hopping down the creek towards our exit. Marty stepped down on a loose boulder and it kicked his left foot out causing him to fall, breaking his ankle. With the amount of boulder hopping left, Marty was not able to navigate the creek bed. I activated my Sarlink PLB for assistance. The Highway Patrol SAR arrived and lifted Marty into their helicopter. The SAR people stated that the signal they received from my PLB was spot on and allowed them to reach us in a timely manner.