California Naturals has limited ingredient grain free options including a lamb formula and a venison formula. I would also look at Sojo's grain free lamb mix. It's freeze dried but a great food made in Wisconsin. Canidae's Pure line is also limited ingredients and they have a lamb, salmon, duck or bison formula. They are made in the US. I also like Wild Calling. It's based in Colorado but they have a single protein line that is awesome.