The girl, named Sarina, disappeared on Wednesday afternoon, Bern police said in a statement.
Informed of her disappearance around 8pm, police launched a search operation throughout the night involving army personnel, firefighters, dogs from Swiss rescue dog service Redog and a search helicopter.
Mountain specialists from Bern and the Swiss Alpine Club were also consulted due to the rough nature of the terrain.
But despite the extensive nature of the search, as of Friday morning Sarina has still not been found.
Sarina is described as 155cms tall, with long, red, wavy hair. She was wearing jeans, a pink t-shirt and black Converse shoes.
Anyone with information should call Bern police on 031 634 41 11.
Photo: Bern police