dDanz27,

Having worked on the Navajo Res, lived in Nevada for 25 years, etc. -keep track of your water. It sounds obvious, but all the other discussion is fluffy in comparison. In Big Bend, or GC a day's hike is from one water source to another. You had better be able to read a map buddy because in a lot of that country there are no trails. Retrace your steps if you screw up.

I have found that hydrated food like carrots, apples, even salad is a big hit in dry country. You may still need to bring extra water for lighter drier foods. Always carry water purification tablets and a water container even for short hikes. The most dehydrated I have ever been was in Montana of all places near the Missouri River when a heat wave sent the temperature to over 112 deg F. The only water I had was air temperature and barely palatable. I didn't drink enough and got in trouble.