I have carried pistols in many ways and under many conditions.

I have always used a combat harness (cavalry holster) when using my ALICE pack but I would think that a "cross draw holster" (per Russ's suggestion) would probably work best under most conditions. Carrying a pistol stuck behind my belt works well but that method is very hard on the pistol and is meant for the short term.

I think it's strange that I have never thought of trying a cross draw holster, but I'm a wee bit strange anyway.

Carrying the pistol in a cross draw holster would make the pistol a part of your "in the woods" EDC and that means that you would have it on you if & when you needed it.