Can't get layers to work properly in 2D,,Layers in Top Down RPG

I'm just beginning to learn Unity...I'm attempting to build the map for a top-down RPG. I know I need to place things on different layers to preserve transparency, but I must be missing something, because spites in "higher" layers (meaning closer to the "foreground", so to speak) are showing up behind spites despite the sprites being on the bottom-most layer. An example:

You can see here that even with the "Ground01" tilemap selected, which I have assigned to the "Grass and Ground" layer (which is the lowest, see below) the grass tile is showing up on top of everything. You can also see the trees sitting behind the cliff, and I have their layer as the "highest".

Here is my layer list:

I'm really at a loss here for what I'm doing wrong and how to correct this so I can simply build this map.

[1]: /storage/temp/167934-unity-layer-04.jpg

[2]: /storage/temp/167936-unity-layer-002.png

,I'm just beginning to learn Unity...I'm attempting to build the map for a top-down RPG. I know I need to place things on different layers to preserve transparency, but I must be missing something, because spites in "higher" layers (meaning closer to the "foreground", so to speak) are showing up behind spites despite the sprites being on the bottom-most layer. An example:

You can see here that even with the "Ground01" tilemap selected, which I have assigned to the "Grass and Ground" layer (which is the lowest, see below) the grass tile is showing up on top of everything. You can also see the trees sitting behind the cliff, and I have their layer as the "highest".

Here is my layer list:

I'm really at a loss here for what I'm doing wrong and how to correct this so I can simply build this map.