Trying to get the legs stronger

On yesterday's hike I carried a 9 pound pack and I felt it.  I could definitely feel the extra weight on the steeper uphills.  So today I did an up-and-back on Cowles Mountain (3 miles) with a 12 pound pack so that my pack for the Grand Canyon hike would seem light by comparison.  I also used my hiking poles today to see how much they help and to see if I'd have any sore muscles after using them.  The hiking poles definitely made the uphills easier.