Congratulations!!
I love that second picture!!
We have a 'designated dig area' in our yard - and "most" of the holes are in that area... but since Denna (EM) is coprophillic (poop-eater)... I can't bury poop in the mis-placed holes to deter digging.
I sometimes throw treats in the "good" holes to promote digging there... which works for a little while.
We should start a Seattle-are Mastiff play group! I'm over in Kirkland. So far, my trainers are affiliated with Cascade Kennels in Woodinville and DoggyHaven in Bothell/Snohomish. I'm always open to learning from new trainers - Denna is probably too old to attend, but I'd still be interested in hearing where your group class is in March.