Received a call from this number, I rejected it since I didn't know where area code 307 is, and they never left a message. I looked the phone number up, and found it's a Wyoming number, and since I don't know anyone in Wyoming, I'm sure it's spam.
I have received numerous calls from this robo source. If you call back, they hit you with the same message that they were leaving when they called you originally...no way to talk to them and ask them to stop. My phone is registered on the DoNotCall Registry.
If you get a call from them, please report it to: https://complaints.donotcall.gov/complaint/complaintcheck.aspx