Possable fan clutch area, but, not with mine when I did the same off roading.
In the same area, you have pullys for your serpinten belt and a tensioner with a pully on it. Good possability on any of them as they have bearings in them. You can use a stethascope for mechenics that have a metal rod on it or a long screw driver. Will motor is running, you touch the mounting brackets that these items listed above are attach to and you can here if there is grinding sounds in there. BE CAREFULL NOT TO TOUCH MOVING PARTS WHILE DOING THIS, I'M NOT RESPONSABLE FOR F/U.
These pullys are what I got a lot of water and sand into and what was making all them noises, my starter went next as the sand got into the armature. Andof course in between the brake pads and rotors and needed turned when pads needed replaced.
Good luck on finding and be carefull as you can usually find where the sounds coming from while motor is running only.