The home on Willeys Lake Road had already collapsed from the flames when crews from North Whatcom Fire and Rescue arrived around 9:30 Saturday night.
A neighbor says the flames and smoke could still be seen Sunday morning.
Sheriff Bill Elfo told the Bellingham Herald that the 72-year-old homeowner was found dead inside.
The man's wife discovered the fire after coming home from shopping.
Fire crews had to bring in tanker trucks full of water to fight the blaze because there are no fire hydrants in the area.
Elfo says it was probably an electrical fire and did not look suspicious.
The Whatcom County Fire Marshal's Office is investigating the cause.