Akart, Bobby. Yellowstone series #3

Author information from author's website

"Modern man had studied the eruption and aftermath of volcanoes on our planet for two centuries, but in the past one hundred years, scientific equipment allowed them to predict the environmental impact. When assessing the fallout of the fourth major eruption of the Yellowstone supervolcano, the prediction models were wrong. No part of our planet will be left untouched by the fallout. Those who weren't incinerated by the eruption will be poisoned by the gas or succumb to the ash mixing with the fluids within their bodies. For those lucky enough to survive the direct effects of the eruption, they were subject to starvation and dysentery as the ash fallout created a volcanic winter. And then, there was the threat of their fellow man."--Provided by publisher