This was handed down to me from my native Wyoming grandmother, who in turn got if from her mother and grandmother before her. It's authentic as it gets! This was the recipe that the pioneers used while crossing the plains in ox-drawn Conestoga wagons, and while living in log cabins on the frontier.
It is essential of course in order to prepare this recipe that you use a Dutch Oven. I've included a photo of one, but if you need more information go to this web site:
Don't be fooled by knock-off imitations: the only "real" Dutch Ovens are made from cast iron, and are designed to be used in campfires. They'll have a lid that has a flange to hold hot coals on top, as well as a large handle to lift it out of the fire. The Dutch Oven needs to be seasoned after purchase, which you can find out about in the above mentioned web site.
To make this recipe, set up a fairly large campfire and burn it down until you have a good deep bed of hot coals. Take the bacon and press individual strips around the inside of the Dutch Oven so that there it forms a complete lining, allowing no part of the metal to be exposed.
Decide whether you want your potatoes with their skins on or off. If off, you'll need to peel them. Then for either option, quarter the potatoes and add them into the Dutch Oven, making sure that none of the potatoes come into direct contact with the bare metal.
Cut the butter into dabs and add it throughout the potatoes. Then open the can of beer and pour it over the potatoes. This will soften them and add a very nice flavor. Cover the potatoes with any leftover bacon strips, and then place the lid on top.
Carry the oven over to the bed of coals. Place it on the coals directly and then shovel some hot coals on top of the lid, as is shown in the photo. Cook the potatoes for about an hour. Remove it from the heat and open it up to allow the potatoes to cool down a few minutes before serving.
A word of caution: when you open the lid after the potatoes are done, be prepared so that if you faint from the overwhelming fantastic aroma that comes out of the pot that you won't fall into the fire or some other dangerous spot. :)