Pyrocumulus cloud

As I write this, the High Park fire is the second largest wildfire in Colorado history, currently at 75,000 acres (over 300 square kilometers, or 115 square miles). It's been burning more than a week, and fighting it has been difficult due to dry conditions, wind, and oppressive heat in the area. I can see the fire from Boulder, but yesterday I got a really good, if terrifying, view of it driving home from the airport. There was nothing but farmland and one low range of hills between me and it. I stopped and took some pictures with my phone: