MARINE CORPS BASE CAMP PENDLETON, Calif. -- “The most uncertain thing in life, is life itself.”The commanding officer's words were carried along by a cool breeze that blew atop San Onofre Mountain, as Lt. Col. Barton S. Sloat spoke to a battalion of his Marines standing in somber silence beside a memorial dedicated to their fallen comrades who were lost in Iraq.The Marines from Battalion Landing Team 1st Battalion, 4th Marine Regiment, Camp Pendleton, completed their ritual of hiking up the steep mountains behind Camp Horno, with stones in hand, to reach a site that has become their own piece of hallowed ground.When the Marines reached the top of the mountain, they saw an unadorned Cross centered and anchored by an array of white and earth colored stones.These stones were carried and placed by other Marines on previous 1/4 hikes as a way to pay their respects to their fallen brothers, said Gunnery Sgt. Dennis Collins, company gunnery sergeant, B Company.“They represent the carrying of the burdens of the fallen Marines who paid the ultimate sacrifice,” said Collins.Shortly after their last deployment with the 11th MEU, almost a year ago, was the last time the BLT hiked the rugged mountains. And now, with less than two weeks before another deployment, 1/4 paid one more visit to the memorial.“We came to pay our respects to all those that gave their lives,” said Cpl. Joseph G. Casillas, squad leader, 1st platoon, C Company. “Ultimately, they sacrificed their lives for the Marines standing to the left and right of them. In combat they are all you have. Hiking up this mountain is the least we can do.”Although the four-mile, two-hour trek, up hillsides as steep as 90 degrees at some points, was physically challenging, the hardest part was emotional.When the Marines reached the mountain top and set stones on the memorial dedicated to those who have passed since the beginning of operations in Iraq, each member of the battalion laid a stone down and paused for a moment to pray or reflect on memories shared with the fallen.According to Sloat, the hike and memorial are not only dedicated to those who have died, but “it helps us rededicate ourselves to making the most of our lives.”