You can not tell from the ingredient list what the source of the ingredient is. Currently in the US two ingredients have been found to be contaminated. But the dog food was made in the US.
Reading the ingredients can give you some idea, however two company have recalled their products, that were not supposed to have rice protein or wheat gluten in them by the company that was subcontracted to produce dog food to a certain formula was adding tainted ingredients against the directions of and without the knowledge of the company who’s name was on the food.
Personally for the above reasons and others, I only feed my dog human grade foods ingredients.

search for the company, brand online they should have a contact us page, then you can ask if ingredients are sourced in the US, not all companies will disclose or simply beat around the bush and say their ingredients are safe
Some websites will say where the ingredients are sourced

This site has managed to do this already and were able to obtain full disclosure from some companies
and some have refused to reveal their sources when asked so you may just want to use this site to pick your food if you don’t get the answer you want

I think that you should check on the back of the box or bag that it comes in.