In article <ff71e2d8-47a2-49ed-b837-c416a8b7d963
@x18g2000prb.googlegroups.com>, miso@sushi.com says...

The JEFX exercise running now at Nellis is supposed to have some sort
of activity over Pahrump. This is the notam for the event.

A0984/10 - QRACA THERE IS A STATIONARY ALTRV IN THE PAHRUMP NEVADA
AREA BOUNDED BY THE FOLLOWING
POINTS: 3622N/11554W 3604N/11554W3604N/11612W 3630N/11630W 3630N/
11610W TO POINT
OF ORIGIN. ACTIVE FROM 10000 TO 14000 WITH HIGH SPEED MILITARY
AIRCRAFT. ALL
NON PARTICIPATING TRAFFIC IS ADVISED TO AVOID THIS AREA. NOTE: THIS
ALTRV EFFECTIVELY
CLOSES V135 BETWEEN
10000 FT-14000 FT DURING THE ACTIVE TIME FRAME. SEE TEXT - SEE TEXT,
22 APR
19:00 2010 UNTIL 22 APR 22:00 2010. CREATED: 17 APR 19:22 2010

This translates to more or less:
There is an altitude reservation in the Pahrump Nevada area bound by
(coordinates) from 10000 to 14000 ft above ground level with high
speed military aircraft. blah blah 22 April noon until 3PM PDT.

I'm told the ground staging is at the Calvada Air Park.

I am not sure if that is a NOTAM or not but as a rule, I would be very 
surprised if they gave an advisory to pilots that was in AGL and not 
MSL.  Just about everything I am familiar with concerning altitudes for 
aircraft is given in MSL as that is what the standard barometric 
altimeter indicates.  Also it would drive the pilot crazy trying to 
figure out AGL, particularly over uneven ground as it would be 
constantly changing.