SAN DIEGO — In-N-Out, the popular fast-food restaurant company, has been around since 1948.

Founded by Harry and Esther Snyder in Baldwin Park, California, the chain is known for its sought-after “animal-style” burgers and old-fashioned milkshakes.

Lynsi Snyder, the granddaughter of late In-N-Out Burger co-founder Esther Snyder, is the president and CEO of the family-run business. She recently wrote a book, titled “The Ins-N-Outs of In-N-Out Burger,” about the iconic burger joint.

The book’s description on the book’s publisher Thomas Nelson’s website details “how three generations have created a thriving, family-owned company, why its fans are so wildly loyal, and what led to its explosive growth and evolution into an iconic part of American culture.”

Lynsi shared on Instagram that she is excited about the release of her book.

“I collaborated with several retired In-N-Out family members to share stories that happened during the 75 years of our special company. It’s been an amazing experience to pull these memories. I want my family to be honored but also share the whole truth. I can’t wait to share this book with you and hope you enjoy it as much as I have enjoyed putting it together! I have waited so long to tell the true In-N-Out Story,” Snyder said.

With locations in California, Arizona, Colorado, Nevada, Oregon, Utah, and Texas, the company is hoping to bring its brand East with plans to open multiple restaurants in Tennessee by 2026.

Lynsi’s book is expected to hit stores on Oct. 17 for $20.99, per the publisher’s website.