Shamrock Farms was founded in 1922 and remains to this day a family owned and operated business. In fact, they operate the largest dairy in the southwest of the United States with their very own herd of 10,000 cows. They offer a full line of daily products and have recently added more food items to the product mix.
I fear I'll be aging myself when I say I even remember when they delivered milk to your door. Their little green delivery trucks could be seen in the wee hours of the morning in most neighborhoods.
The top picture shows their headquarters located on the west side of Phoenix.