In honor of the beloved burger chain’s opening of its first location in Oregon (which just so happens to be just down the road from the Bathroom Readers’ Institute), here’s a quick look at In-N-Out.

Harry Snyder and his girlfriend Esther were living in Seattle when they got married in 1948. Shortly thereafter, they moved to Baldwin Park, California, where they opened In-N-Out Burger, the Golden State’s first drive-through hamburger restaurant around the corner from their new house. During these early years, it was a pretty humble operation; the stand was 10 square feet. Harry woke up every day before dawn to grab the freshest ingredients he could find from local produce and meat markets, while Esther handled all the bookkeeping. After long days on the grill, Harry worked in the garage on a two-way speaker box so his customers could place orders without getting out of their cars.

Within 10 years, In-N-Out had five locations in the San Gabriel Valley. Customers couldn’t get enough of the Synders’ quirky burgers like the “Double Double” (two beef patties, two slices of cheese) and “Animal Style” (beef patty grilled in mustard with diced grilled onions, cheese, and special sauce). The chain’s locations became a magnet for local teenagers and hot-rodders, which is one reason why Harry decided to invest in the construction of the Irwindale Drag Strip. What was sold at the racing arena’s concession stands? In-N-Out burgers.

Harry was also a big fan of It’s a Mad, Mad, Mad, Mad World, a 1963 comedy film that features various characters scrambling to find a robber’s stolen loot buried near a series of palm trees that form the letter “W.” This is the reason why most In-N-Outs still have crossed palm trees planted in front of them.

To this day, In-and-Out’s loyal customer base continues to flock to its various locations to dig into its burger and “secret menu.” Unfortunately in the mid-2000s, management had to do away with an official policy of preparing special order burgers of any size after a group of people requested one containing 100 beef patties at a location in Las Vegas. The most you can order at an In-N-Out today: four patties with four slices of cheese.