Hence the interested in a map.
Presently without ATC contact, glider flight from Southern
California to the Reno area requires three codes: 1201 for Joshua,
1200 for Oakland - unless they've recently changed, and 0440 for
NorCal. It's easy to think there is no problem if you don't confirm
with each center that they have you.
If I call and say "Clear of Rxxxx" Joshua may just say "Glider 2JS
squawk VFR, frequency change approved". I could think VFR meant 1202
and likely be wrong and now off their frequency. Not a good way to
impress the controller I may want clearance from tomorrow, or even see
in the Thai restaurant this evening!
Jim