Two women were arrested after spray-painting a treasured East Bay rock formation in Sunol Regional Wilderness, police reported Sunday.

Authorities with East Bay Regional Parks Police said the women painted rocks at Little Yosemite, one of the East Bay’s popular haunts for hikers and sightseers, around 2:20 p.m. July 7.

Sima Mohmand, of Union City and Elaha Qudratulla, of Fremont, both 22, were arrested after a witness took a photo of them painting the rocks, police Capt. Alan Love said Sunday.

The could face felony charges for defacing the rocks and also charges for environmental damage to what was described as a “fragile ecosystem and sensitive watershed.”

The women appeared to be using red or orange paint on the bluish-white rocks to paint a memorial in a photo park police posted on their Facebook page. Love said it could cost between $3,500 and $5,000 to remove the paint.

Sunol Regional Wilderness is a scenic 6,858-acre park of blond, rolling hills covered in oak woodlands typical of the Diablo Range. It lies north of Calaveras Reservoir in southern Alameda County.

Little Yosemite, which does not resemble the famous scenes of the Sierra Nevada national park, is a gorge on Alameda Creek about two miles from the park’s visitor center.

The area that features waterfalls after storms is accessible to the public because of an agreement with the San Francisco Water Department, which owns the property.

The parkland was first inhabited by Native Americans and then ranchers; cattle still are allowed to graze in the park, which is located near Fremont in the rugged East Bay back-country.

Love said the women were cited and released from Santa Rita Jail in Dublin because of COVID-19 guidelines meant to reduce overcrowding and spread of the disease.

Staff writer George Kelly contributed to this report.