The slide happened Saturday morning, sending debris and mud into the Cedar River. The blocked river moved through six properties, but has returned to its normal flow.
The King County Sheriff's office reported there were no injuries, minor damage to properties, and standing water in some homes.
Kent Fire Department Capt. Kyle Ohashi said the slide was about 300 feet high and 300 feet across its base.
A stretch of the river remains closed for all activities, and the slide is being monitored for any more movement.
Tape remains around the slide area to keep the public away, as a geologist who surveyed the damage says trees dangling by just roots will break away in another slide - but when is unclear.
Several government agencies are expected to remove slide debris and trees that have built up in the water on Monday.
Officials say the river will re-open after the debris is removed, and the area is safe.