Blackbird Mountain Guides no longer operating months after deadly Castle Peak avalanche

Blackbird Mountain Guides has ceased operations, the company's website says, months after an avalanche near Castle Peak killed nine people on a backcountry ski trip the company was leading.

A total of fifteen people had been part of the trip, according to officials, leaving a total of six survivors. The incident was the deadliest of its kind in state history and the deadliest avalanche in the entire country since 1981. 

Three of the nine people killed in the avalanche were Blackbird guides.   

The company had faced numerous questions over the incident, which happened on Feb. 17 during the middle of a significant storm, with scrutiny over the choice to continue the trip despite the severity of weather conditions. 

In August, the company released a preliminary report by backcountry skiing and avalanche professional Don Sharaf, which assigned the company no blame. 

A California Division of Occupational Safety and Health Administration investigation, however, led to the guide company receiving citations totaling over $150,000 in proposed penalties. Blackbird Mountain Guides disputed the findings, filing a formal appeal back in August.

The citation appeals are still pending, according to OSHA. CBS News Sacramento has reached out to Blackbird Mountain Guides for comment.