Called my land line. Don't know anyone in Montana so just let it ring off the hook.
Since Philip (above) also reported the call, and MrNumber.com says it's scum, it's now BLOCKED.
Caller ID showed "Bozeman MT"; we answered because we have relatives there; no one was on the line. I agree with 'dews' that it was probably a robo-caller checking for legit telephone numbers.