I have downloaded a lot of GeoTiffs of historical topo maps from the USGS (https://ngmdb.usgs.gov/topoview) at the 1:24000 scale. I am wanting to Mosaic these together to eventually clip to watershed boundaries, however the white collars on the outside are proving to be a headache. I have not been able to find a solid answer on these forums or anywhere else on the internet of how exactly to remove the collars.
Does anyone have an answer?
Any help would be appreciated!