Doco Overboard hits it. Cooking in the field is just as much about enjoying the experience as the meat, though the meat is darn good. If you have a grill in the truck, foil can help avoid over drying the meat over what is likely to be imperfect heat. No acids in the foil, though. Just butter (if desired) or some bacon wrapped around the loin. Dry spices to taste. Keep it on the rare side, and with a low fat content they will cook FAST. If you are doing this ye olde rustic way, it is strongly advisable to wait until the fire is fully down to strong coals. A lot of flame, not to mention soot from sorta-dry camp wood, will not do your loin any favors. Fat coating (butter) or wrapping in bacon becomes almost necessary here. Toothpicks or butcher's twine to hold the bacon on, stainless meat staples if you are really fancy.
Sort of off topic but if you get any rabbits, they make mighty tasty campfire fare. Field improvise a spit and two spreaders, roast and enjoy.
Sort of off topic but if you get any rabbits, they make mighty tasty campfire fare. Field improvise a spit and two spreaders, roast and enjoy.