I have done some searching and am not finding any help so far with this issue I am facing, so coming to you folks!
What I am trying to do is add some more map pages to an already existing index layer. I do not want to recreate one from scratch as I need to maintain all the existing map page numbers as they are today and just add more. We have page numbers for our county (Pierce) from 1 - 1800's. When we extended out into King County, we have pages that are in the 5000's. The extension into Kitsap County to the north is 6000's. I need to now incorporate an area extending into Thurston County (See pic - area circled in red) and will gave these be 8000's.
I am unsure how to just add more pages and also be able to do all the calculations for the new pages, such as providing the page labels to the N, NW, NE, W, E, S, SW, SE for the new pages that use the already existing pages as well.
If anyone knows how to do this, I would be so grateful! I am running ArcGIS Desktop Advanced 10.5.1 (ArcMap) and I also have access to ArcGIS Pro.
Thanks much in advance!