Anyone down there? image - Strider Mountain mod for Half-Life 2

AT 30,000 FEET... you are almost 6 miles (9.7 km's) above sea level. The human body is not made for these conditions. Temperatures can plummet to -60F (-51C), the brain is starved for oxygen and each step is a new experience in pure agony. It's difficult to breathe. It's difficult to think. It's difficult to move. And you still have to endure another 444 feet (0.14 km's) to get to the peak. So much for the good news. STORYLINE: SURVIVE the SUMMIT ...The rebels are losing the battle against the strider onslaught that keeps growing. To help turn the tide of war you need to destroy the source of the Striders. That source is at the summit of what the rebels call, StriderMountain. There is only one way to get into the mountain geography and it's extremely dangerous terrain. The danger proves to be too much and you are forced way off target. Now, you must fight your way through the Combine Mountain Base Camp because it's the only entry to the mountain...