http://www.nifc.gov/nicc/sitreprt.pdf, full title is National Interagency Coordination Center Incident Management Report.
It’s updated quite regularly. No pretty pictures or links to news stories, just lists of how many wildfires are in the United States (also information at the end about wildfires in Canada, although that part is only updated weekly). Includes information like how many large fires, uncontained fires, how many of various types of teams are deployed, change in size of various fires, etc.
Got the link from a friend who is a volunteer fire fighter.