How to make only part of my scene foggy

Is it possible to make just certain areas within my scene foggy?

As an example player starts in low valley and all is clear but when player climbs the mountain the area becomes foggy.

thanks

Using particles is the only solution.

This package has been recommended http://www.jocyf.com/utilsEnglih.html

There are volume fog assets available, check the asset store.

Such as this one

There’s also vertical fog which could be suited to your needs:

Youtube link