Finding out Reason for DROTAM

[Selous Scout]

I was checking out Skyvector looking at fires in the Western States and I noticed this huge DROTAM west of Portland.

Is there a way to check out the reason? I went to notams.aim.faa.gov and it's listed but no reason why. And it's from SFC-92000 ft? Really? I'm not in the area just curious.

 

[that_guy]

What I know is that it is a warning to all aircraft of uas activity. The fact that it list surface to 92,000ft makes me thing this is likely military related or test flights of a uas