Combine many nonadjacent rasters into one

[DanShaffer]

I have hundreds of DEM 1x1 degree raster files.  They are under several dozen metro areas.  Therefore, there are gaps and they are not all touching.  All have same number of "Bands" and have same projection, pixel type, depth, etc.  I want to combine them into one layer.  I have tried the following:

Mosaic to new raster:  creates raster file with name I gave it but says "Raster Data Objects Error:  Invalid raster dataset.  Failed to create raster layer."  when I try to open it.

Merge tool in raster calculator:  gives me error when I try to combine the rasters.

Maybe if someone could give me the best tool to use in this regard as most of these tools seem to be for adjacent rasters. Maybe this is what is causing me problems.  Thanks!

[DanPatterson_Retired · Accepted solution]

Did you explicitly set the raster extent in the Environments section (bottom right of the tool interface) to be the union of inputs for the mosaic to new raster?  Are you saving the file to a local folder?  Details of your exact procedure would narrow down your issue.

[DanShaffer]

Thanks, looks like the union of inputs for the raster extents did it based on my test with 5 of them.