The Mountaineers, a Seattle-based climbing and hiking group, first came up with the idea of 10 essential items you should take with you when you venture out into the backcountry. The original list first started showing up in their outdoor programs in the 1940's and 50's.
To this day the list is still valid, however, most folks add to it with their own list of essentials. The 10 original essentials are:
- Map
- Compass
- Flashlight or headlamp with fresh batteries
- Extra food
- Extra clothing
- Sunglasses
- First aid supplies
- Pocket knife
- Matches in waterproof container
- Fire starter such as a candle
Map and Compass
These days a lot of people opt solely for a GPS system. They are relatively cheap and easy to use these days. Plus, they are kind of fun. However, you should never rely on a single point of electronic failure such as GPS when you are exploring an area you are not extremely familiar with. Learn to use a map and compass. Yea, it's old school but the map doesn't lie and it won't die on you. If you lose the compass, you can still use the topo map to terrain navigate.
Flashlight
Not only will you use the flashlight at night but it can be used as a signalling device if you get stranded or have an emergency. You will want to make sure you bring enough spare batteries. I generally take an extra pen light with me just in case.
Extra Food and Clothing
I would say that these categories leave a bit to your own interpretation. With clothing you should bring extra layers of light, warm material. Definitely something that would whisk away sweat or dampness. Of course, it would depend on the time of year and where you are outdoors to decide what and how much to bring. Generally speaking, extra thermals and a waterproof jacket would be the bare minimum in most scenarios. If I was doing extreme winter camping, I would definitely bring extra socks, gloves/liners and head gear.
Food will depend on how long you will be gone. Generally speaking, if I was hiking in to a wilderness area or someplace similar, I would carry an extra couple of days’ worth of high energy bars over and above what I would normally carry. Energy bars and gels have tons of calories and are relatively light to pack.
Sunglasses
I hate to squint. If you aren't hiking in the woods and it becomes sunny you may want sunglasses. Even if you are in the woods, you may want the eye protection that lenses will afford you from branches and the like. There are sunglasses that have interchangeable lenses that you can use. Most have clear, dark and yellow tinting. The yellow tint is helpful for hiking/biking in the woods if it's not bright enough for the dark lenses.
First aid supplies
There are first aid kits for weekend hike and bike excursions. There are first aid kits for day trippers and there are first aid kits for epic adventures. I think at a minimum for a weekend hiker/biker you would want to pick up a lightweight med kit that would include sterile dressings, bandages, tape, towelettes, antibacterial ointment, butterfly closure and tweezers.
Pocket knife
The most versatile item on the list. Can be used for food preparation, gear repair, first aid, making kindling or other emergency situations.
Matches
You'll want to bring plenty matches. Just make sure you put them in a waterproof container. Make really really sure it's waterproof. Like a lot of gear, test your waterproofing at home before you are out in the woods or desert, etc.
Fire starter
Bring a few candles along to help get your fire going. They can also be used as night-time illumination if the need arises.