Hi Elizabeth
There is a PDF file that I have (downloaded from a scottish site that I will have to refind) which has all the parishes for Scotland & associated RDs
This is what it gives for Fort Augustus
Name County From To Rd Numer Current RD Ref
Fort Augustus Inverness 1892 1970 Old RD 92 a2 Today's RD 235
Fort Augustus Inverness 1971 1971 Old RD 92 Today's RD 235
Fort Augustus Inverness 1972 Today's RD 235
Fort Augustus or Abertarff Inverness 1855 1891 Old RD 92 2 Today's RD 235
(removed the pre 1855 as presumably you are searching post 1855 for a death)
I'll post the link for the file when I find it
Fort Augustus is a district within Inverness - as is Abertarff - so perhaps you search both of these - depending on the dates
There is probably a file somewhere that equates RD numbers to names!
Trish
PS Hello Annie

Edit: I had a slightly better look at my file & discovered it is not a parish list - but a District list! so you have both the district number and name - sometimes I worry myself - and I still can't find it online