A group of 80 Royal Marines Reservists has just completed ‘Commando Strike 09′, a demanding two-week high-altitude mountain training exercise in the Sierra Nevada mountains in northern California.The Royal Marines are the UK’s mountain warfare specialists, a skill they were called upon to use on their first foray into Afghanistan during Op JACANA in 2002.The mountains in the UK aren’t high enough to conduct high-altitude training so the reservists went to the United States Marine Corps’ Mountain Warfare Training Centre at Pickel Meadow, north of Yosemite National Park. With altitudes three times higher than Ben Nevis (the highest mountain in the UK) this was an ideal training area for the reservists to be able to practise their skills. Even the base camp, sitting at 6,000 feet (1,829m), was higher than anywhere in the UK and they therefore undertook some particularly arduous training at altitudes of up to 12,000 feet (3,658m).The air was thin, the temperatures high (up to 95 Fahrenheit), and they each carried in excess of 70lbs (32kg) on their backs for most of the time. Back-breaking work even at lower altitudes. Despite their part-time status, the reservists are as highly trained as any regular Royal Marine and must maintain the skills and fitness that are expected of a Commando.Some of the reservists, many of whom have served in Afghanistan with their regular counterparts, used up part of their allocation of holiday time from their civilian jobs for the exercise.The aim of the exercise was to allow the reservists to practise the skills required for this environment, such as climbing, abseiling, crossing rivers and even the use of mules to allow them to carry more equipment. After six days of acclimatisation during the skills training phase, they deployed on a four-day field training exercise based around a scenario in Afghanistan where they applied these skills.Using the California training area allowed greater freedom of movement than would have been available in any similar facility in Europe. The conditions in the Sierra Nevada mountains are also quite different from that of Europe, and its arid soil and hardy vegetation are reminiscent of the mountains of Afghanistan.Indeed, all US Marine Corps units deploying to Afghanistan carry out their preparatory training at Pickel Meadow.The Royal Marines Reserves regularly conduct training in demanding environments to ensure they remain ready to support Royal Marines’ operations anywhere in the world. Last year they held cold weather exercises in Norway and jungle training in Brunei.Information and photographs supplied by UK MOD.  All photos Crown Copyright 2009.