In-N-Out, the beloved West Coast institution, opened its doors on Oct. 22, 1948 in Baldwin Park, California.
Since its opening in southern California, the chain expanded to neighboring states including Arizona, Nevada and Oregon. Just in 2010, Texas received its first In-N-Out locations, with restaurants added in the Dallas-Fort Worth area, Austin and San Antonio.
There are 334 locations in six states.
Earlier this month, the burger joint's parent company announced the first Houston area locations.
SEE MORE: Where the Houston In-N-Out Burgers will be located
In-N-Out is popular for the simplicity of its menu, offering three burger options - single patty hamburgers with or without cheese, and the Double-Double, which boasts two patties with two cheese slices. The lure of In-N-Out, though, can arguably be found in its secret menu. The most popular custom way to get a burger made is by "Animal Style," which includes a healthy slathering of its Thousand Island-based sauce.
Due to the simplicity of the menu, more patrons became drawn to the restaurant over time for the speed of service, hence the name "In-N-Out."
An official party to celebrate the anniversary is on Nov. 17 in Pomona, California.
SEE MORE: 7 ways Whataburger wallops In-N-Out Burger
How does In-N-Out stack up to the Texas favorite Whataburger?