Having Issues with River Flow Maps in Photoshop

[Azhek_Ahriman]

Hello, I'm relatively new to the whole mapping thing, and decided as such to basically go through the Israh tutorial for my first world with a little less of Israh's signature geography. This has gone relatively well with the seemingly unexplained exception of the river flow maps in Photoshop. The Israh tutorial suggests that once I save the river flow maps and stick them in Photoshop, I should be able to select all the black pixels in the image and delete them, presumably with the magic wand tool that Israh uses for the rest of the tutorial. I’m having an issue where I can’t select these pixels, no matter what combination of magic wand, color range selection, or anything else that I try. Has anyone else had this issue, and if so does the community have any ideas for a work-around or alternate solution. Loving my mapping tools to death so far, and looking forward to getting a decent regional map going, complete with rivers!

Edit: Linked two examples of the river flow files I'm working with

Seryth_Rivers_Medium.png


Seryth_Rivers_Small.png