Thanks everyone,
Brenda, I meant that the logs would rise above ground level, and then be covered with at least 6 inches of topsoil, so no part protrudes visibly from the bed, sprouting could still be an issue with some trees, but these logs aren't going to sprout, that's for sure.
Paul, you may be right about it being a bit more effort, but unless you've got some 250 year old oak logs, i think it's a manageable task with a shovel alone.
Anyway, I'm back in Montana and I have another sight that looks good for a Hugulwick, so I'll keep you all posted as the seasons change.