Just like the picture says, a feed bear is a dead bear. If people continue to feed wild bears then they will continually roam into the camp grounds to look for food. So please do not feed the bears. They are not normally aggressive, but are known to be able to open up a car like a pop can literally if they smell food. So do store it in your car or tent. Check with the rangers what methods they recommend. Now days I think they have special lockers since storing food by the pulley method in trees is not a option in this area.
At the higher elevations, bears are not a problem. But, come twilight, mice begin scurrying around, hungry and ready to do damage. I accidentally left a couple of powergels in the mesh side pocket of my pack. The mice chewed through the mesh, punctured the packets and devoured their contents. They also chewed holes in the tent of some fellow travelers.
Make sure to hang all of your food and toiletries away from your tent. The mice did not heed the "Do Not Disturb" signs we hung on our tents so I wouldn't recommend this course of action. They are also quite noisy neighbors and scurried around all night (especially after consuming those power gels). Calls to the front desk did little to correct this problem. But, at least they didn't chew through the tent fly and get in during the night.
Many people experience the effects of altitude at Whitney's higher elevations. It is advisable to camp at Whitney Portal the night before hiking to give yourself at least a little time to adjust. Drinking lots of water also helps, as does avoiding alcohol.
I went up to over 11,000 feet right from sea level and got my first case of minor altitude sickness. The guide provided my with Diamox, which really seemed to work, although it caused a tingling sensation in my arms and legs which was a bit unnerving.
It is recommended that you drink at least 3 liters a day up here. If you're doing more than an overnight visit, you will not be able to carry all of the water you will need. There are water sources on the main trail. As for the Mountaineers Route, you're looking at one of them. Instead of water purifiers, we used pills to chemically treat the water. I would recommend them as they take up far less space than a purifier. You have to let the water sit for 30 minutes before you can drink it, so plan your water stops and supply accordingly. The pills create a horrible aftertaste too, so you will want to bring either the neutralizing pills which take the chemical taste away or some sort of flavored drink mix like gookinade, or both.
I was pretty nervous about drinking water from the lakes and streams we found along the way. But everyone assured me that the tablets would kill any bacteria in the water. They seemed to work because I didn't have any problems, either during or after the trip.
Weather in the High Sierra is generally more predictable and settled than that you find in many other mountains of similar stature. Generally, unlike the Front Range of Colorado, you don't have to be off the peaks by 1PM due to daily thunderstorms. That said, this is still the mountains and anything is possible. Snow can fall at anytime. Lightning can kill. Winds can howl. One lady climber, I know, took a picture of a funnel cloud in the backcountry to the west of Mt Williamson that the Weather Bureau says is the highest recorded tornado. Be prepared. A new foot of snow can quickly change things! A lightning storm out in the open above timberline terrain, can be more excitement than you want!
"While enjoying the scenic and recreational values of the Alabama Hills, hikers, rock climbers and sightseers should use utmost caution at all times. The few remaining mine shafts and tunnels in the general area should be avoided because of the extreme hazards they represent. False bottoms might give-way or tunnels collapse because of deteriorated shoring timbers. The Alabama Hills are beautiful, but there are hazards that could injure the unwary or unprepared visitor."
I took this from their website. I think it was no use telling you this in my own words.