The Copper River flows some 300 miles through Alaska, and the salmon that attempt the journey up that river are some of the richest, tastiest fish in the world.
The Copper River king salmon has a firm red flesh and a rich, nutty flavor that really calls for a minimalist approach when grilling. I almost always do them on a cedar or alder plank. Plank cooking deepens the flavor while letting you use high temperatures to seal in the juices.
Use a food-grade plank that’s been soaked in water for at least half an hour. Set your grill up for direct cooking at medium-high heat (about 450°F). Oil the skin side of the salmon and season both sides with a little sea salt.
Put the plank on the grill by itself for about 5 minutes, or until you see the first wisps of smoke coming from the board. Flip the plank over and put the salmon on skin side down.
Close the lid on the grill and cook for 10-15 minutes. Salmon is best medium rare, so take the fillet off when it starts to flake, but is still a little translucent red inside – about 135°F internal. Remember that the fish will continue to cook a little once it’s off the heat, so you want it to be slightly underdone when you take it off.