Cantonal police were searching the area with the help of an army helicopter.
Initial estimates found that up to 4 million cubic meters (140 million cubic feet) of rubble had been dislodged. Villages were equipped with an automatic alarm system after a massive rock fall in 2012.
Residents of the village of Bondo were still unable to return home on Thursday.
Missing group found in Italy
A group of six people also feared missing in the landslide was found safe on Thursday across the border in Italy, police spokeswoman for Graubunden Chiarella Piana said.
Police had initially indicated that they were unsure whether or not the group had left the affected region.