West RouteThe Beckey book lists three routes up Old Guard. The West route seems the easiest and most practical if you are doing the Ptarmigan Traverse. We were traveling from North to South on the 'PT', day 3 about 3:00PM, just before passing through another col at the south end of LeConte Mountain...which is a long ridge of multiple peaks. The primary photo of Nick and I has Old Guard on the left and Sentinel on the right. We are at 7300 feet at the photo, so you have less than 1000 feet to the summit. We aimed for gap between Old Guard and Sentinel. You have several options once in this gap between the two peaks, but still on the West Route. With a high snow year we opted to go high on the snow before we got onto the rock. The first short lead we did use one nut. Climbing was not real difficult. We found a ledge that took us slightly north, but still on the West side of Old Guard. We were able to scramble after first protected short pitch to the summit following easy moves of loose rock. Down climbing was equally easy until the last 60 feet where we found a sling, doubled with one of ours and rapped. Round trip from 7300 foot Col where we left our packs was about 3 1/2 hours. From here we moved from the LeConte Glacier to traverse downward to the South Cascade Glacier and further down to White Rock Lakes. The views on this clear day were outstanding, south to Glacier Peak, Dome, north to LeConte, Formidable, Spider and many more. It was great to do it on the 'PT', but I can not imagine making it a destination in itself. I guess we all have to decide for ourselves what makes a peak worth it.
Getting ThereWe used the Eric Sanbo route page for the Ptarmigan Traverse. To get to where I have started my route description and the Primary ID photo use stage 4 of Eric's report: http://www.summitpost.org/stage-4/175423.
The main page for this mountain describes the approach from LeConte Lake which will get you to the same starting point of my description. Or, you can come from the Suiattle River, up to Cub Lake, Itswoot Ridge, over Spire Pass to this same starting point. All of these approaches require 2 or 3 days just to get to this starting point for the last 1000 feet of climbing the mountain. Whatever route you come in on, you choose how to get out by the same or traverse like we did from North the South on the Ptarmigan Travese.