Latt..
Your last Pic there is a good one and now that I see it a little better I am not so sure what I find in my yard is the same thing.
Mine if not near that white but has more of a very light tan color to it, and after they mature and start to shrink they turn darker brown.
I have never seen one get near as large as yours or look that white.
Softball size is about as big as mine get.
This summer or fall I will post a pic of them when they start showing up.
I am leaning more towards what I have may be the dangerous ones that Bcastle mentioned and will sure treat them like that until I find out different.
PS - I walked a mile today with a good looking red head (my wife) down our black top road and could hardly watch where I was going for trying to spot morels along the roadway edge
Still no luck, but it rained agian today and it has really warmed up so perhaps they will be out soon.
Thanks
TNhunter