Mt. Lukens is located on the northeast side of the Crescenta Valley, above the George Deukmejian Wilderness Park. It is a distinctive, landmark mountain that rises high above the valley and is dotted with radio towers.
Sister Elsie Peak on Mt. Lukens is the highest point in Los Angeles at 5074 feet. Due to its height and location, it is an ideal site for what the USGS calls on topo maps an "Electronics Site," or what people in the communications business call an "Antenna Farm." Once on the peak, you'll be able to see virtually all of the City of Los Angeles and surrounding cities, making this peak ideal for line-of-sight communications, like microwave and other radio services like police and fire communications.
To locate the cache, you must, obviously, find your way to the top of Mt. Lukens. There are multiple routes to take. A great resource to find the route best suited to your taste is the Sierra Club Hundred Peaks Section webpage for this peak. (My favorite is the route I used when I placed the cache - via the Deukmejian Wilderness Park. This is Route 3 on the Sierra Club webpage.)
There's some interesting history (and controversy) regarding "Sister Elsie" and the naming of the mountain. For a quick, but comprehensive look, check out the Sierra Club "Summit Signatures" webpage for Mt. Lukens.
Once on the peak, continue to the coordinates posted. You'll be traveling through the thick of the antenna farm. The coordinates will take you to a L.A. County benchmark. From this point, the final cache location is 70 feet away at a compass reading of 350 degrees (or basically north). The actual cache site has something in common with the location of the posted coordinates.
Just in case you need some extra help, decode the clue and check out the pictures.
During warm weather, be on the lookout for rattlesnakes at the hiding spot. Use a stick to poke into the spot before reaching in with your hands.
The cache container is a camouflaged military decon container measuring about 3"x5"x2". Only room for small trade items in this one. Once you've made a trade and signed the log, please be sure that the lid is on light and that you replace the container exactly as you found it, including the items used to keep it out of sight.
Have fun!