Juglans Californica or J Hindsii or J Major.The place where you find it would be usefull in picking one of these 3.They all have red walnuts similar to J Neotropica and all are edible.
Californica and Hindsii are endangered species,better leave the nuts on the tree( maybe try one or 2) or plant them/ sell them to otthers that would plant them.