The Cowlitz County Coroner's Office does not file or issue death certificates.

To request a death certificate, please contact:
The Cowlitz County Health & Human Services/Vital Records Department

Cowlitz County Health & Human Services
1952 9th Avenue, Longview, WA 98632
(360) 414-5599

As of January 2021, Death certificates are not open to the public.  This means, not just anyone can obtain a death certificate for someone.  You will have to prove your relationship in order to obtain one.  
Please see the Health Department for details