I own "Mt. Whitney Adventure Map" "© 2006 Sierra Maps".
It's way too dark and almost useless in low light conditions.
Do you believe that Tom Harrison map is better?
I don't know which that one is, but from what I can garner on the interwebs, your map uses increased/darker coloration to perhaps denote more depth and dimension. The TH maps are quite simple in this respect, using lighter colors similar to a traditional topo. But, no matter what map you have, it's worthless unless you know how to read it.
Are you sure that you GPS is not broken? Have you tried updating firmware?
I recorded "good enough" tracks with my own Garmin 60CSx up to Whitney Crest and LBL.
Sorry you're not understanding my point, so I'll try to rephrase. GPS are not as simple to use as people think. They are not full (or fool) proof. The batteries can die at odd times. You need to be able to set the unit up to be tracking your movements if you want to use it to maintain a heading. In answer to the OP question, your phone's battery may not last the whole day (especially if it is searching for a signal, maybe try the "airplane mode" to stop the search?).
As for my own GPS functioning, this is the first time it's given me a wacky location, so I found it funny. It's recently been updated, so I just have to tinker with it.
To the OP: getting a map is step one. Do you know how to read a topo?
Personally, I don't think a topo is necessary on the main trail: going slowly, paying attention to your surroundings and the trail/boot track and those around you are more important skills. At the end of the day, many are just in a hurry to get down, and stop paying attention to what they are doing. Don't fall into this trap.
-L
