I have 6 DEMs, all of which are the same resolution, projection and coordinate systems. I would just like to make them into 1 DEM so that I can mask them to an AOI I am working in. I looked up the help button and it showed me the tool and how to get to it. I have spatial analyst extension on. it says go to customize<toolbars<production something. Either way, I click on customize and toolbars and this next thing I am supposed to click is not an option. Is there a way to get it to appear or is there another way to merge these DEMs. I am planning on doing slope, hydro, ARCSWat, and adding multiple layers into this and joining them later as well as disaggregating the resolution from 10 to 1. I know the assumptions that will have to be made but that's what my stakeholder wants.