The accident occurred on June 12 near Nam Quang suspension bridge in Bao Lam Commune.
According to local authorities, Ly Thi Trang, 37, from Thai Nguyen Province, was travelling along the highway from Ha Giang to Cao Bang when a large rock suddenly broke away from a cliff and fell onto the road.
The rock struck both Trang and her motorcycle, causing her to fall and leaving the vehicle severely damaged.
The woman was taken to a local hospital, where her condition later stabilised before she was transferred to Ha Giang for further treatment.
Following the incident, Bao Lam authorities warned of landslide and rockfall risks along National Highway 34, particularly during the rainy season.
Motorists have been advised to slow down, remain alert for warning signs and avoid travelling through high-risk areas during periods of heavy rainfall.
