Interesting. I'd never heard them called zombie fires, but I'm familiar with the phenomenon.

Our vacation home was in the middle of a cedar forest and the soil is the peaty mix that's described in your Wired piece. Neighbors had a firepit constructed on their property and had a fire burning there for several days while they camped. They put the fire out, including pouring water on it, before they left.

A few days later someone who was driving by noticed smoke in the woods. They called the fire department and the firemen found that there was a peat fire smoldering in the woods well away from the original firepit. It was heading for some nearby homes.

I was surprised how far the fire moved laterally. Scary stuff.

The South Canyon fire of 1994 killed 14 firefighters. The canyon is a few miles west of Glenwood Springs.
Some attributed the fires that still burn in 19th century abandoned coal mines under the area. There are cracks
in the earth that let the fires escape.
The fires are the source of heat for a small hot springs that attract locals.
There was another fire there last August.