My uncle Bill called the other day and somehow we started discussing the beetle that he and Jesse discovered and gave to my mom. He identified it as a June Beetle and I think he's correct. According to my 5 seconds of internet research, I've tentatively identified it as a ten-lined june beetle (Polyphylla decimlineata) which can be found here.
I think we have another species of beetle down here in California which is also called a june beetle. Ours sounds like a bomber and is bright green. I keep hoping to find a dead one since I haven't had the heart to kill one. This one landed on Chris' swim trunks last summer.