Did anyone else notice the FAA flight restriction that popped up over that Nevada site last week?

Saw this flagged on FlightAware last Tuesday. The restriction came up with almost no notice and was listed under some vague military exercise designation that didn't match anything in the usual databases anyone could cross-reference.

What gets me is the timing. There'd been a cluster of reports from locals in that area the week before, couple of odd lights and one bloke who filmed something hovering low near the ridge. Then suddenly the airspace shuts down. Coincidence is possible but at my age you stop believing in convenient coincidences.

Anyone managed to get the actual NOTAM reference number? Would be worth archiving that before it quietly disappears. I've seen these things get scrubbed from the public records before, happened with a site in Lincolnshire back in 2009 and nobody believed me at the time. They did eventually.

@FreddieLewis which exact designation was listed? that's the bit that matters most imo. I've seen a few of these over the years and the ones that don't match any known exercise code are usually worth digging into further. the Nevada ones especially. got a screenshot?