If you could sing a few bars of the “trailing” noise it might be helpful. Does it sound like a cowboy song when they are riding the trails? Could it be some brush got snagged last time you did some off roading and it’s rubbing against a tire? Why don’t you jack it up and get it on 4 good jack stands so the wheels are off the ground. Then start it up, put it in first gear and let it idle see if you can narrow down where the noise is coming from.