Bug bombs and pesticides are too indiscriminate, and in this case unnecessary.

My suggestion is bring a raw pork butt roast with you, some string, a bucket, and a thimble of liquid soap.

String up the roast near their nest, put the bucket 2/3 full of water under it, and dump in the soap. The yellowjackets will get a whiff of that roast ripening, go after it and gorge themselves. They can't fly away, so they drop to the ground and land in the bucket and drown.

I have filled a 5 gallon bucket like that back in Walla Walla. Cleared out all the yellowjackets in the neighborhood for the rest of the summer.

You might have to put it in a place where the bears and critters can't get to it easily. But I've strung up roasts at hunting camp more than once, and it works in a day. It'll work on wasps and hornets.