Here's the article: http://www.avweb.com/avwebflash/news/GPS-Interference-NOTAM-For-Southwest-226365-1.html

Excerpt:

Although the FAA doesn’t go into detail, it seems the military is testing something that can disrupt GPS over a huge area, centered on China Lake, California, home of the Navy’s China Lake Naval Weapons Center. On Tuesday, June 7, the FAA is warning that GPS signals down to 50 feet AGL could be “unreliable or unavailable” between 9:30 a.m. and 3:30 p.m. local time over a radius of 253 nautical miles, which includes the L.A. Basin, Bay area and Las Vegas.

And here's the official FAA notice https://www.faasafety.gov/files/notices/2016/Jun/CHLK_16-08_GPS_Flight_Advisory.pdf (so this is not just another wild internet rumor).

I haven't seen any major stories in the news about GPS not working in California today - so I'm assuming they just wanted to be extra cautious about anything potentially involving flying safety.

Still, this is yet another reminder that a GPS is not a substitute for a map & compass...

Will this affect normal "terrestrial" GPS functions. The notice doesn't flat out state that and seems directed at airplanes.

My concern is that I and some colleagues will be collecting GPS data fixing the location of the funny fossil bones that intrigue us during the times indicated.

Bring a sextant.

until just a few years ago the University Of Minnesota offered a class on using a sextant.outside of the military does any know if there are still hands on class's someplace?

Not that I know of, but there are a myriad of online references (including the official government publications in pdf form) that are almost as good as a class (minus the hands on of course). Once you get the hang of swinging a sight (not that hard) the rest is math and attention to detail on the forms.

Just google "celestial navigation classes" and you will find some. Various sailing and yachting schools still offer hands on courses. There are also a goodly number of online & home study classes.

A fascinating book to read is "Sextant: A Young Man's Daring Sea Voyage and the Men Who Mapped the World's Oceans" by David Barrie