If you aren't able to find Bisquick there, you can make a pretty reasonable "fake" this way:
Sift together 8 1/2 cups all-purpose flour, 1 tablespoon baking powder, 1 tablespoon salt, 2 teaspoons cream of tartar, 1 teaspoon baking soda, and 1 1/2 cups instant dry milk (powdered milk). Use a wire whisk to make sure all dry ingredients are blended well. Once blended, cut in 2 1/4 cups vegetable shortening (not oil), such as Crisco (not butter flavor). This can be done using the metal blade of a food processor if the bowl of the processor is large enough to hold the volume of the ingredients. This makes about 13 cups of biscuit mix, but I've made half a recipe, which is a little more manageable in my food processor.
Keep in a container with a tight-fitting lid in a cool dry place. Use within 10 to 12 weeks.