The National Park Service has identified two people killed in a recent rockfall in Yosemite National Park as Georgios Theocharous, 51, and Ming Yan, 35. The San Jose couple was killed when falling rocks hit their rented Dodge Ram on December 27. The rocks hit with enough force to knock them into the embankment of the Merced River. The couple was pronounced dead at the scene by officials.
The rockfall happened around 9:00 a.m. on El Portal Road near Big Oak Flat Road. As a result, the NPS closed Highway 140, directing drivers to Highway 41/Wawona Road or Highway 120. The roadway leads into Yosemite Valley on the east side and is one of three entrances on the west. The road closely follows the Merced River on one side and is up against the valley's rocky hills on the other. The rocks reportedly plummeted from 1,000 feet up the hillside down to El Portal Road. According to park officials, around 185 tons of rock covered 500 feet of the road. Officials are investigating what may have caused the rockfall.
According to a National Park Service Tweet, El Portal Road was closed for several hours. However, they reopened the road the following day.
Unfortunately, rockfalls are not uncommon in this area. On December 30, Big Oak Flat Road was closed due to a rockfall incident and reopened the following day. Earlier in December, the area was closed due to another rockfall. According to the NPS, over 1,000 rockfalls have happened in the last 150 years. Rockfalls are a natural process that helped create the "beautiful and changing scenery" in the park. But the NPS acknowledges that they due present hazards to visitors and wildlife.
Rockfalls can happen due to glaciation, bedrock fractures, vegetation, and weathering. According to the NPS, "Over long periods, water flowing through fractures decomposes the bedrock in a process called weathering. Weathering loosens bonds that hold rocks in place." However, they are not able to predict when a rockfall will happen. In 2021, 47 rockfalls occurred, resulting in 4,670 tons of rocks. The numbers were below average, which coincides with the below-average precipitation. The largest happened at El Capitan during heavy rains in October of 2021.
