I learned early while serving in the Army that your backpack is your home away from home. It carries all of your mission critical equipment and anything that can make a rough time in the woods a little bit better. While serving with the 3rd Ranger Battalion I carried a Large Alice pack.
It was stuffed to seam popping capacity with ammunition, MRE's, and water. I learned that every ounce in your backpack feels like a pound on your legs. We learned there were items you need and items you didn't need. There are a few items that are requirements for fun and safe backpacking operations. I will begin with the basics, items that are required for survival.
We will start with the big three Water, Food, and Shelter. You must have these items in your pack no exceptions. Water is first on the list because it is the most important. You can survive 3 to 5 days without water in a survival situation. But remember we are out on the trail moving and sweating. Your body will expel sweat at a scary rate when you are exerting yourself. There is a great Army study on hydration here... In essence this study says the more you exert yourself or the hotter the climate the more water you need to drink. We were always told at lease a quart of water per hour. That is a lot of weight in your pack. You can get to feeling like this poor guy.
Back in the day we carried everything in the trusty canteen both the one and two quart variety. They did the job, but while I was in we were issued a new product called the Camel Back. These things are great. The container is much lighter allowing you to carry a larger volume of water with less weight. Today these hydration systems are the standard. I carry a 3L on most of my afternoon hikes. They make bladders as large as 10L so you can tailor the size of your water supply to the mission at hand.
If you have a local water supply and don't want to carry all the water you need with you there are also some great water purification devices ranging from drops, tablets, filters, and UV lights. These can be pricy, but can save you a lot of weight.
Food, I love my food. It is the fuel that keeps us going. While you can survive for days with out it I don't suggest it. In the Army we had MRE's. Many guys didnt like the MRE's but I did. They were a great package they had everything including toilet paper! One or two of these can keep you going for all day. MRE's can be expensive, around 60 to 70 dollars a case of 12. I tend to build my own MRE's. They are simple food items that are easy to prepare on the trail and stuffed into a a zip-lock bag. They can include freeze dried foods, fruits, nuts, cookies, Ramen Noodles, drink packets, or snack packs. Pack foods that will keep your energy up and pack enough to keep you going in case of an emergency.
When it starts to get cold wet and nasty you need to shelter your body from the elements. Shelter can be as simple as a poncho, or as elaborate as a 4 season backpack tent. You need to have enough equipment to keep you dry and warm. Being cold and wet not only makes you feel miserable but you are inviting hypothermia or other cold weather injuries. I always carry at the bare minimum a poncho, and a tarp. You can use both of these items for a field expedient shelter. While in the Rangers we did not carry tents, too much weight. We erected poncho hooches like the one to the right. While not the best they did the job to help keep you warm and dry. Along with your poncho remember a good pair of gloves, a good jacket or sweater, and an extra pair of warm socks. Dry warm socks keep your feet very happy.
Although this is a short list it is important. Water, Food, and Shelter help to keep you comfortable and safe. Make sure they are in your pack! I will continue later with other important items that are great to have in your pack.
73's and keep climbing!