Pine trees near Lake Tahoe are being poisoned in what authorities believe are a series of interconnected incidents in the popular tourist community on border of Nevada and California.

The incidents have damaged nearly 30 trees, some reportedly more than a century old, and caused hundreds of thousands of dollars in losses.

Officials in Nevada said 28 trees were poisoned at Burnt Cedar beach, a restricted-access beach located on the north-east shore of Lake Tahoe. Six trees were also damaged in 2022, another six in 2024, and 16 more were discovered this year. In a statement released on Thursday, authorities said that the incidents appear to be connected, causing an estimated $300,000 in losses.

No suspect has been identified or arrested.

“We take these crimes very seriously and will utilize every available resource to identify and apprehend the person or persons responsible,” said the office of Darin Balaam, the Washoe county sheriff, in a statement. “The destruction of mature trees in the Tahoe Basin and the environmental damage caused by these deliberate acts are unacceptable.”

The most recent incidents were reported in late July and early August. On 24 July, deputies responded to the beach after a strong odor was detected near a large pine tree. Soil samples collected from the area had an odor consistent with other incidents related to the pine trees at the property, according to the county sheriff’s office.

Officials returned on 2 August after more trees were found with a substance around their bases. Authorities believe the most recent incident occurred sometime between 11.30am on 1 August and 5am on 2 August.

Authorities are still investigating the substance used to poison the trees in the residents-only beach in Incline Village. Investigators have collected soil samples for testing to determine which substance was used and whether the same substance was involved in each incident.

In some instances, officials found holes had been drilled near the roots of the pines in Incline Village.

Authorities said that, based on the estimated amount of damage, the person or people responsible could face felony-level charges.

Incline Village is a scenic mountain town that has recently attracted some of the world’s wealthiest, earning it the nickname “Income Village,” as billionaires including Oracle co-founder Larry Ellison and Google co-founder Sergey Brin have reportedly purchased homes in the area.