Boulders from the Rimrocks crashed down onto a home on Laredo Place in Billings on Saturday at about 1:30 a.m.
The boulder was about half the size of the home; one person was inside at the time, and was helped out of the home by a neighbor before emergency crews arrived. There were no serious injuries reported.
Battallion Chief Ed Regele of the Billings Fire Department said that the amount of rockfall was "significant," and that the force of the boulder knocked the house about 10 feet off of its foundation.
The road was closed and some nearby residents were briefly evacuated.
There is no word yet on how much damage the boulders caused.