Perhaps white slime mold. Appears after heavy rain in good soil. Helps in decomposition of soil. Not harmful to anyone or anything. Unsightly, you can break it up and turn it under in your soil. Also called dog vomit slime mold - nasty, huh?

Susan

Here is a link that might be useful: White Slime Mold

I cant tell you what it is, but I have had the same problem when using a lot of organic and getting a lot of rain. What ever I had went away about as fast as it came. I did not notice any harm.

Larry

I do think it is white slime mold. For the record, slime mold comes in a variety of colors.I often see it in yellowish, orangeish and tan shades. I see it only after lots of rain and warm to hot, humid weather. It goes away, as Larry noted, about as fast as it came. One day it is there, and then suddenly it is not. I just ignore it, but if looking at it bothers you, you can scoop it up and toss it onto the compost pile.

Susan's link didn't work for me, so I'll see if I can link some white slime mold images below for you.

Here is a link that might be useful: Images--White Slime Mold Fungus

Thanks everyone!
I'm convinced, and relieved! You guys are the best. Have a great rest-of-the-weekend!

Kristen