From this vantage point, on all but the foggiest days, the peak of Mount San Gorgonio is visible, rising from the San Bernardino Mountains and topping out at 11,503 feet above sea level. These mountains are the reason why this area is a desert. Moist air from the Pacific Ocean is pushed east by wind  towards Joshua Tree National Park, but the mountains are too large an obstacle for wet, heavy clouds, so most of the moisture is discharged before the clouds can make their way over to Joshua Tree. Precipitation on the west (ocean) side of the mountains can be more than double the precipitation on the eastern side.