Missing specific base game maps.

So I have no idea why, but I installed Gmod on my new laptop recently and I’ve noticed I’m missing map files for the base game. I have no idea if this is due to some misstep I did in uninstalling Gmod on my previous computer (which seems highly unlikely) or something else is up with my game. I bought it and installed it via Steam, and I’ve been able to run everything else fine, including the maps I do have.

I should also note that I have verified the integrity of the game files multiple times now, and each time it says that everything seems to be in order, but obviously that is not exactly the case. At this point I’m decently confused on why I’m missing these maps, and I’ve exhausted all my known knowledge on this subject (which wasn’t very much to begin with) so I’ve finally resorted to doing what I should have when I began having this problem.

Any help at all is literally (figuratively) appreciated a ton!

What maps are you expecting to have? You won’t have any other game’s maps unless you mount them.

I was missing gm_flatgrass until one of my friends sent me a file that had the map included in it, but besides that one I was told I should currently have gm_fork and gm_genesis as base maps. I’ll be honest and say I’ve never played on either of those two maps, so I don’t know if my friends telling me that I should have them are just being the idiots they are, or if I actually should have them. I’ve tried downloading maps with those names from the Steam Workshop, but they never appear in the map menu.

It is also a possibility that if I should indeed have these maps, I screwed myself over, seeing that I am still pretty new to the whole PC thing, but I feel that losing key files to a game that automatically downloaded is a bit far fetched even for someone such as myself, but who knows.

Thanks for the help, and sorry for the essay long explanations!

the only base maps gmod comes with is flatgrass and construct