This tutorial will teach you how to easily mount Black Mesa Source to GMod so that you can use the materials and models from it.

First, locate your GarrysMod/garrysmod folder. By default, it is C:\Program Files (x86)\Steam\SteamApps\common\GarrysMod\garrysmod. If you have changed it, this will obviously not be where your GarrysMod/garrysmod folder is.

In your GarrysMod/garrysmod folder, find another folder called "cfg", open this folder then open mount.cfg in notepad or any other text editor.

Now you need to locate the file path for your Black Mesa installation.
For the Steam version, the default file path is

For the mod version of Black Mesa, the default file path is

If your file path is different (e.g. if Black Mesa is installed on a different hard drive, etc), use that file path instead.
Now we will add this file path into the mount.

For the Steam version, add this:

For the mod version, add this:

If your file path for Black Mesa is different, use that instead of the ones given above.

Unless you have changed your mount.cfg before, it should similar to this:


Make sure that you do not have a double slash (//) before "bms", as this will disable the mounting.

Black Mesa should now be successfully mounted on GMod.

Now you can open a Black Mesa Source map (I'm not sure if the maps are added to the list, if they aren't, download a Black Mesa map on the workshop) and there shouldn't be any missing textures or errors.