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 on Windows, it is

If you are unsure, skip to the How to Find Your File Path section. This will show you how to access your installation's files and allow you to easily find the "garrysmod" folder.

In your GarrysMod/garrysmod folder, find another folder called "cfg". Open this folder, then open the mount.cfg file inside using notepad or any other text editor.

Now you need to locate the file path for your Black Mesa installation. If you do not know how to do this, scroll down to the How to Find Your File Path section.

For the Steam version, the default file path on Windows is

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

If you use one of these default locations, you should verify that it is correct by following the How to Find Your File Path section.

Next, we will add a line to mount.cfg to tell Garry's Mod where our Black Mesa installation is.
Between the curly braces {}, add a new line with the following:


For example, with the default Windows file path, you would add:


Here is an example of a correctly configured mount.cfg to show where exactly to add this line.

Make sure that you do not have a double slash (//) before "bms", as this means the line will be ignored and will disable the mounting.
Black Mesa should now be successfully mounted on GMod.

There has been some confusion about the file paths in the comments, so I'm hoping this section will make it clearer. This section explains how to find your Black Mesa file path, but you can apply the same logic to find your Garry's Mod file path if you need to do so.

By default on Windows, Black Mesa is installed to:

Your installation may be in a different location for whatever reason - maybe you have a separate hard drive for games storage, or you're not running Windows.

To find where your instalation is stored, right click on Black Mesa in your library, and click "Properties"


In the properties menu, go to "Installed Files" and click "Browse".

This will open up a file browser showing your installed game files. You can then copy the path to the "bms" folder from here, and use it with the steps given in the guide.

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.