DARRINGTON, Wash. — The new sign for Steelhead Drive is fresh green with white lettering. But the road it announces is a mere stub of pavement, ending in a massive gray-and-brown scab of mud, clay and broken timber where a rural Washington state neighborhood once sat.

A rain-soaked hillside collapsed suddenly on March 22, 2014, sending 18 million tons of sand and soil thundering across a river valley north of Seattle, destroying dozens of homes and entombing 43 people in the deadliest landslide in U.S. history.

A year later, as a bill moves through the state legislature to improve mapping of landslide-prone areas and give local planners a better idea of risky development areas, the mangled cars and homes have been cleaned up, but reminders of loss are everywhere.

“Those thoughts and memories are out there every time you head down the valley,” said Dan Rankin, the mayor in nearby Darrington.

Yet living with the scarred landscape also reminds them of how they tirelessly searched for victims, of their gratitude for the well-wishes they received and of the millions of dollars in contributions that poured in for housing, counseling and mortgage payments on destroyed properties.