I am working on an undergraduate Ethanol plant siting project, the study area is Chouteau County, in Montana.
One of my layers is a DEM, which will be transformed into a Slope grid. This layer is a mosaic of 107 smaller DEMs, the problem is that 2 parts are missing, see attached picture.
contact the producing agency and see if the data exists but just hasn't been posted. Secondly, you may have to consider limiting your study area if the whole area is a "nice" versus a "need". You will not be able to produce data for the missing areas since they are quite large.
Is it just the USGS stuff? In the US? The SRTM derived stuff is free and easy to work with for US data. Somewhat less so for other areas, but..... Just go identify what the best/most suitable data they have for missing areas and download it.... If it is around your area in Canada they might have "fixed" versions
