We were driving along the northern loop near El Capitan when we noticed several people in a field to the left of the road standing and pointing up to the rock face. So we stopped because this usually means that someone has spotted a climber or climbers climbing El Capitan. Sure enough we spotted at least one climber with the naked eye. I took several shots with the SD1M and 20-200 zoom lens at 200mm. Upon examining the images, sure enough there were TWO climbers. They were using conventional climbing techniques (ropes, pitons, etc.). Understand that the Yosemite Valley floor is at approximately 3,900 feet (1.19 Km) and El Capitan peaks at over 7,500 feet (2.29 Km), a difference of 3,600 feet (1.10 Km).