The Two-Rope Counterbalance Method
1. Divide your food into two bags, weighing roughly the same. Let's call those Bag A and Bag B.
2. You have two ropes or cords. Let's call those rope 1 and rope 2.
3. Tie rope 1 onto a rock, but you could use a rock sack. If possible, find a live tree limb that is 20 feet up, and ideally it tapers from the trunk out to very skinny where you want to hang this, ideally 10 feet out from the trunk. It also helps if the tree limb is slightly down-hanging, because that makes it harder for a bear cub to climb out on it. Throw one end of rope 1 over the limb, and you have two ends hanging down temporarily.
4. Tie Bag A onto one end of that first rope. Prepare to pull on the other end of the first rope.
5. Take rope 2, and loop it around Bag A so the middle of that rope is rubbing against the first rope. Both ends of rope 2 are temporarily dangling on the ground.
6. Pulling down with the opposite end of rope 1, slowly pull Bag A up until it barely touches the limb. As you did that, the second rope is still looped around Bag A, and it is still dangling down. The second rope will later be the "pull-down rope."
7. Still with the opposite end of rope 1 in hand, reach up as high as you can reach on that rope. Twist that rope to make a small loop. It will be between the middle and the opposite end of rope 1 still in hand.
8. Choices here. If you have a small carabiner, you can put it through the small loop to snap around rope 1. If you do this wrong, the carabiner will fall to the ground. If you do it right, the carabiner will be caught in the loop.
9. Attach Bag B to the carabiner. If you didn't use a carabiner, then make a half hitch around the bag's neck. In either case, Bag B is now attached to the low end of the rope 1.
10. You have some excess length on rope 1. Tie a bowline or any closed loop on the end. Stick the excess length into the neck of Bag B with just the bowline loop exposed and hanging just an inch below Bag B. Alternatively, you can dangle the excess length through the Bag B attachment loop.
11. Now with rope 2, slowly pull both ends at the same time, and this will cause Bag A to slowly descend, and that will cause Bag B to slowly ascend.
12. When both bags are dangling together, stop pulling. The bags are counterbalanced. Ideally, they are several feet higher than what you can reach.
13. There should be just a tiny bit of loop dangling an inch below Bag B.
14. Now with rope 2, let go of one end, and pull on the other end. That rope will pull out around Bag A and drop free. You're done. There is nothing hanging to the ground.
In the morning, grab a stick or tent pole, reach up and catch that tiny dangling loop. Grab that end of the rope, pull down Bag B. Release it from rope or carabiner. Lower Bag A down, then remove your rope from the tree limb.
When you read this, it will seem complicated. Practice it a time or two, and it will become second nature. With lightweight food bags for one person, one person can do this solo. With heavy food bags for a group, it will probably take two people to do it.
It is thought that a bear can easily reach up as high as a man can, or maybe a hair higher. So, you want to get the food bags and loops a couple of feet higher than that. That's why you need to start with a limb that is about 20 feet high.
It is thought that few adult black bears can climb a tree very far. However, black bear cubs can climb very well. So, the mother bear typically sends one of her cubs up the tree to get the food. Some bears will actually attempt to chew the entire limb off the tree trunk. Sometimes the cub will climb high above the tree limb and then jump outward, attempting to grab the food bags on the way down. That is called a Kamikaze Bear.
For extra credit, take an ordinary empty brown paper sack and tie some bright white cord on it, and dangle it carelessly by another tree. That is the decoy. The bear may go after it first, and the noise will give you more time to wake up and defend the real food bags.
For more extra credit, take your metal pots and pans and tie them around the trunk of the tree at about 5 feet off the ground. Place one small rock into each pot. If the bear tries to climb over that, it will make noise to warn you.