I have downloaded DRG's (.sid) files for the entire state of West Virginia, in hopes of mosaicking them together for use in my study of historical land use patterns within watersheds.
My question specifically is how to mosaic them together seamlessly without the black and white backgrounds surrounding them currently.
Below is an image of just all the raw files loaded and displayed in ArcMap. There are white areas where two images overlap and black areas as well (I turned off most of the black background in the symbology settings)
A more fine-scale example below shows the same area with one specific layer turned on (left) and the same later turned on (right)
Is there any way to mosaic these images together for a seamless product that could be used to clip to individual watershed boundaries and for digitizing features within those boundaries from this mosaic?
Any help would be greatly appreciated!