I received these pictures and email below. We are unable to answer his question and hoped someone could help. Hi Jan, We live just south of Ontario near the Snake River. Our property is very alkaline. We get lots of meadow mushrooms in the spring and fall if the weather cooperates. The mushroom in the photos is the only one I've ever seen in this area. I grew up in this area and have spent a lot of time outdoors in the last 70+ years. I appreciate you sending these photos around to see if anyone can identify it. I looked at tons of photos on the internet and couldn't find any that looked similar. Thanks again, Mike Eden