Start with fresh, cleaned fish. Keep the fish cold until they're ready to can, not more than two days.
Remove the tail, head, scales, fins, and skin, then wash to remove all blood.
Cut your salmon filets into smaller pieces that will fit easily into pint jars.
Put two to three inches of water in your pressure canner and heat it to simmer.
Prepare the jars, making sure they're sterilized and clean.
Fill the jars with the salmon, leaving an inch of headspace. You do not need to add any water or broth. If desired, you can add ½ teaspoon of salt per jar.
Wipe the jars with a clean, damp cloth to remove any food particles or fatty deposits.
Then, place a hot lid on the jar. Screw the metal band onto the jar until it is fingertip tight. Resist the urge to overtighten, as this can cause the lid to buckle.
Place the filled jars on a rack in the canner, leaving room for steam to flow freely around the jars. In canners that are deep enough to allow you to stack jars, make sure you use a rack between the layers.
Put the canner lid on the canner. Heat the canner until you see the steam escaping from the open vent. Once it starts to do this, vent steam for 10 minutes.
Close the petcock or place the pressure regulator on the vent pipe. Allow the pressure to reach 11 lbs pressure for a dial gauge canner and 10 lbs pressure for a weighted gauge.
Process the jars at 100 minutes for pints or half pints (adjusting for altitude, see notes).
When the canning time is done, turn off the heat and allow the pressure to return to zero. Wait an additional fifteen minutes, then remove the lid. Let the jars cool for another five minutes in the canner, then take them out and allow them to cool at room temperature for 24 hours.
Check the seals, label, and store.