Although the cause of death for John Gerrish, Ellen Chung, and their daughter Miju is still under investigation, all public areas along the Merced River, between the towns of Briceburg and Bagby, California, were shut down by the Bureau of Land Management due to the presence of toxic algae.

According to New York Daily News,

The Bureau of Land Management has shut down a 28-mile stretch of land along a California river due to the presence of toxic algae, just weeks after a family and their dog were found dead in the area.

All recreation sites along the Merced River between Briceburg and Bagby, in Mariposa County, will be closed until at least Sept. 17, officials announced Friday.

“The safety of visitors to our BLM-managed public lands is a top priority,” BLM Mother Lode Field Manager Elizabeth Meyer-Shields said in a statement.

“These algal blooms can produce toxins that can make people and pets extremely sick. We will continue to monitor for the algae’s presence and look forward to when the public can safely recreate in the Merced River.”

Anyone found in the area is subject to a fine of up to 12 months in jail.

Signs warning of toxic algae were already posted along the riverbed when John Gerrish, Ellen Chung, and their 1-year-old daughter Miju were found dead near the Devil’s Gulch area in mid-August.

A cause of death has still not been discovered for the family or their dog, although officials have ruled out physical trauma like a shooting or an assault.

The site was initially closed down after investigators feared a leak of toxic gasses from an old mine in the area.