Current CAL FIRE trucks are 4 wheel drive off-road heavy trucks. They're shorter than municipal or airport trucks, for dirt roads with tight turns. They use a 500 gallon tank with a foam system.
[1] https://www.fire.ca.gov/what-we-do/fire-protection/mobile-eq...
Compare for example these French forest fire trucks: http://www.sides.fr/en/french-standardised-vehicles/
Or this range of vehicles from a Spanish manufacturer: https://www.iturri.com/en/vehicles/emergencies-and-fire-figh...
Probably another example of path dependence?
> Oshkosh Corporation (current; won rebuy competition)
and that's part of the private equity consolidation of emergency vehicle manufacturers from another comment [1] in this post. Perhaps that means there could be more compact, maneuverable, cabover designs of commercial fire trucks!
The photos might have some tilt-shift-like effect going on.