Kourtney Kardashian's son experienced an "awesome" birthday celebration this weekend.

Kourtney and her partner Scott Disick threw a cowboy-themed fete on Saturday to celebrate Mason's second year on earth.

The afternoon function was held at grandparents Kris and Bruce Jenner's Calabasas, California, home.

Event planner Sharon Sacks ensured that all the children had ample entertainment.

"It was a Wild Wild West theme," a guest told Life & Style magazine.

"There were haystacks, ponies, goats and pigs. The front yard was literally turned into a petting zoo; it was awesome. "

The 75 attendees were well cared for. The partygoers were indulged with lavish entertainment and food.

"There were burgers and a Hansen's cake for the kids and adults," the guest recalled. "And there were bandannas and other cowboy props for guests to take, as well."

Mason seemed to have enjoyed himself as much as the other revellers.

"Kourtney and Scott were really attentive to Mason," the guest went on. "They wanted to make sure he had the best time."

Gifts were abundant as partygoers took home goodie bags.

Mason went home with a special gift from his uncle Kourtney's brother Rob.

"I got him a miniature grand piano!" he gushed to the magazine.