I played around with this a bit, and I wasn't able to get this to work with the #FIX directives in the individual SRV files either. Not 100% sure why; I did notice that one of them incorrectly specified the unit order as ENU instead of NEU for the location data, which I presume is a typo. Anyway, here's how I DID get it to work:
Comment out (or remove) the #FIX directive in each individual SRV file
Create a new SRV at the top of the project tree, call it "GPS" or "GPS coordinates" or something and make a corresponding SRV
Put both of your coordinates into this file as follows:
#units meters order=NEU
#fix 0DATUM N35:48:34 W85:21:04 1100f
#fix a:0DATUM N35:48:35 W85:21:04 1100f
This is a nice, clean way to manage your GPS coordinates on a large project anyway.
Screenshot attached!
Spike and I will both be unavailable for a few days, so don't panic if additional questions go unanswered until sometime next week.
PS - with caves this close, I'd have just run a survey shot from one zero datum to the other anyway, even if it's over a hundred feet. Much more accurate, especially if you're going to have overlapping passages when you draft the plan view.
"Although it pains me to say it, in this case Jeff is right. Plan accordingly." --Andy Armstrong