Saw this and had to stop scrolling. Been tracking airspace restrictions around Nevada for years and this one caught my attention too - the NOTAM had unusual coordinates that don't align with any of the known test ranges. Checked it against the Nellis boundaries and it didn't match up.
What gets me is the duration. Most temporary restrictions for exercises are short windows, 2-3 days max. This one sat there for nearly three weeks with no associated military exercise announced anywhere that I could find.
Someone on another forum suggested it was drone testing but that doesnt explain the altitude ceiling. Way higher than you'd need for standard UAV work.
Anyone managed to pull the raw NOTAM data and cross reference with satellite pass schedules for that period? That would be the first thing I'd want to look at. There was a similar restriction back in 2019 near Tonopah that nobody ever got a satisfactory explanation for either.