SEATTLE — For the last three years, when April Fools’ Day came around, Jay Blasi got a phone call or e-mail saying the only tree at Chambers Bay, with the waters of Puget Sound serving as its picturesque backdrop, had fallen down.

It wasn’t a joke when Blasi, one of the course designers, got an early morning call saying a catcher’s mitt-sized chunk of the tree had been hacked away.

“We’re all just crossing our fingers and hoping some way and somehow the integrity of the tree can survive,” Blasi said Thursday.

Officials at the site of the 2015 U.S. Open and 2010 U.S. Amateur about 40 miles southwest of Seattle seemed to get some positive news Thursday, a day after the vandalism to “Lone Fir” was discovered by maintenance crews on their early morning rounds. Officials believe either late Tuesday night or early Wednesday morning, someone hacked away at the tree, possibly with an ax.

Tony Tipton, project manager for Chambers Bay, said a pair of arborists visited the course Thursday to give an initial inspection on whether the tree could be saved. Tipton said the person hacked into the tree about 3 inches, roughly 20 percent of the tree’s diameter.

Before being fully briefed on the initial inspections, course general manager Matt Allen said the arborists were more optimistic about saving the tree than expected.

“They think there are some options for being able to save it, or attempt to save it, using some of their expertise on previous trees that have been vandalized or damaged,” Tipton said.

Pierce County has offered up a $1,000 reward for information in the case. Messages left for Pierce County Sheriff’s Detective Ed Troyer were not returned Thursday.

The Douglas fir sits behind the 15th green and near the 16th tee of the highly acclaimed public course that was awarded the 2015 Open in February, an unprecedented coup for a course that only opened last summer.

Chambers Bay was designed to be a links course from the beginning, with no trees on the course itself. But Blasi and his colleagues working for famed course designer Robert Trent Jones Jr. noticed the fir tree had some personality. As the course began to take shape, designers waffled with the idea of keeping the tree or ditching it.

It many ways, the tree has become the signature image of the course.

“Every time I made a trip up there, I made a stop by the tree,” Blasi said. “It became part of the Chambers Bay lore and family. It really kind of turned into an icon.”

The tree will receive a second opinion from another arborist Monday.

Also receiving a second look is the level of security at the course, which has a public walking trail snaking through the dunes and mounds that create the course’s unique makeup.

Tipton said there have been a handful of small incidents of mischief since the course opened last summer, the most serious a broken bench.

In the short-term, additional security will patrol the area at night.

“More than anything, people are discouraged by the act of vandalism to the property, whether the golf course or the trail,” Allen said. “The trail and the facility people have come to embrace and enjoy.”

Chambers Bay is managed by Kemper Sports, the same company that manages the Bandon Dunes Golf Resort. Allen left Bandon Dunes to become general manager at Chambers Bay in March.