20" Limited Tire Options

[thehaitian]

First, I am a noob, and apologize for my noobism's and poor search-fu as I imagine this has been covered.

That being said, what options do I have for getting new tires on the 20" Limited rim. The stock tire appears to be some odd size that only results in primarily road only tires.

I had Nitto Terra Grapplers on my Tundra and loved them; I'd like something along those lines.

Thanks in advance.