Eighteen of those 24 victims have been positively identified, the Snohomish County medical examiner's office said Monday afternoon. Previously, the official death toll was 21, with 15 victims identified.
Twenty-two people remain missing, authorities have said.
Steve Harris, a division supervisor for the search effort, said search teams are learning more about the force of the March 22 slide, and that is helping them better locate victims in a debris field that is 70 feet deep in places.
"There's a tremendous amount of force and energy behind this," Harris said of the slide. He didn't provide further details.
Harris said search dogs are the primary tool for finding remains in the small, mountainside community about 55 miles northeast of Seattle. He said searchers are finding human remains four to six times per day. Sometimes crews only find partial remains, which makes the identification process harder.
A makeshift road completed over the weekend links one side of the 300-acre debris field to the other.
Searchers have had to contend with treacherous conditions, including household chemicals, septic tanks, gasoline and propane containers. When rescuers and dogs leave the site, they are hosed off by hazardous materials crews.
Volunteer Cameron Smith was born and raised in the valley and has been at the slide site every day.
"When you see it up top you don't realize quite how it is till you get down there," he said.
Smith said he's happy to be of use, but he admits the long days are taking their toll on search and rescue crews.
"Some of the guys are starting to run on fumes because they've been up there for seven eight nine days, you know," he said. "I'm glad that right now there's something I can be doing."
Gov. Jay Inslee on Monday asked President Barack Obama for a major disaster declaration in Snohomish County to make programs available to help individuals, households and businesses.
Last week, a federal emergency declaration was approved that provided a federal disaster team and specialized personnel to the slide area.
Members of the Seattle Seahawks football team and Seattle Sounders soccer team were scheduled to visit with community members Monday evening.
18 identified victims so far:
The Snohomish County Medical Examiner's office says they have 24 mudslide victims in their custody, of which 18 have been identified:
18. Gerald E. Logan, 63, from Arlington, WA
17. Sanoah Huestis, 4 months, from Arlington, WA
16. Judee S. Vandenburg, 64, from Arlington, WA
15. Amanda B. Lennick, 31, from Arlington, WA
14. Shelley L. Bellomo, 55, from Arlington, WA
13. Hunter Ruthven, 6, from Arlington, WA
12. Julie A. Farnes, 59, from Arlington, WA
11. Alan M. Bejvl, 21, from Arlington, WA
10. Leon J. Regelbrugge III, 49, from Arlington, WA
9. Joseph R. Miller, 47, from Arlington, WA
8. Summer R. Raffo, 36, from Arlington, WA
7. Lewis F. Vandenburg, 71, from Arlington, WA
6. Shane M. Ruthven, 41, from Arlington, WA
5. William E. Welsh, 66, from Arlington, WA
4. Kaylee B. Spillers, 5, from Arlington, WA
3. Linda L. McPherson, 69, from Arlington, WA
2. Stephen A. Neal, 55, from Darrington, WA
1. Christina A. Jefferds, 45, from Arlington, WA
22 still missing:
1. Dequiletts, Ronald M. 52 Arlington and Bothell
2. Durnell, Thomas M. 55 Steelhead Dr., Arlington
3. Gullikson, Bonnie J. 91 SR 530 NE, Arlington
4. Gustafson, Mark J. 54 Steelhead Dr., Arlington
5. Hadaway, Steven N. 53 Steelhead Dr., Arlington
6. Halstead, Jerry L. 74 Steelhead Dr., Arlington
7. Halstead, Gloria J. 67 Steelhead Dr., Arlington
8. Harris, Denver P. 13 Steelhead Dr., Arlington
9. Harris, Steve 52 Arlington
10. Harris, Theresa 52 Arlington
11. Miller, Larry 58 Arlington
12. Miller, Sandra 64 Arlington
13. Regelbrugge, Molly K. 44 Steelhead Dr., Arlington
14. Ruthven, Katie 35 Steelhead Dr., Arlington
15. Ruthven, Wyatt 4 Steelhead Dr., Arlington
16. Satterlee, Thom 64 Steelhead Dr., Arlington
17. Satterlee, Mary 61 Steelhead Dr., Arlington
18. Slauson, Lon E. 59 Steelhead Dr., Arlington
19. Spillers, Billy 30 Steelhead Dr., Arlington
20. Spillers, Brooke 2 Steelhead Dr., Arlington
21. Webb, Delaney M. 19 Steelhead Dr., Arlington (alternate address is Marysville)
22. Mangual, Jovan E. 13 Steelhead Dr., Arlington