Trails and campgrounds near where a family of three and their dog were found dead last month have closed because of “unknown hazards,” according to news outlets.

The bodies of Jonathan Gerrish, Ellen Chung, their 1-year-old daughter, Miju, and the family dog, Oksi, were discovered in a remote area of the Sierra National Forest near the south fork of the Merced River by search-and-rescue workers on Aug. 17, the Mariposa County Sheriff’s Office said in a news release. The family was found on the Savage Lundy Trail, according to CNN.

Sierra National Forest officials announced Saturday that the area where the family was found will be closed until Sept. 26, CNN reported.

“Designated recreation sites, roads, and trails in proximity and/or leading to this location will be off limits to public,” national forest officials said in a statement.

The family’s cause of death remains a mystery as authorities are waiting for toxicology reports, CNN reported.

Toxicology results could come as early as Wednesday, Kristie Mitchell, spokesperson for the sheriff’s office, told CNN.

Gunshots, or any other type of weapon, and chemical hazards have been ruled out as causes of death, according to CNN.