A lot of the risk in the high desert of the western US is the ubiquitous sagebrush. Old growth sagebrush is basically a short tree and it burns pretty easily and very hot (excellent wood for grilling though). Fortunately, the large plants of the high desert (sagebrush, juniper, etc) grow very slowly.
When lightning or people start a fire in the desert, both relatively rare, they tend to be limited by two things. First, if areas that have been burned out sometime in the last century or two, the plants haven’t grown back enough to really support a proper wildfire, so it is easier to contain. Prior burns are a natural firebreak and they last a really long time. Second, the high desert of the US is an active volcanic province. There are fresh basalt flows everywhere, some less than a thousand years old, in the terrain. It takes tens of thousands of years for these to support enough plant life to carry a burn. These natural barriers place limits on where they can go and how far they can get.
The desert does have fires but they tend to be muted and often self-limiting because large contiguous regions of dense fuel aren’t as common.
When lightning or people start a fire in the desert, both relatively rare, they tend to be limited by two things. First, if areas that have been burned out sometime in the last century or two, the plants haven’t grown back enough to really support a proper wildfire, so it is easier to contain. Prior burns are a natural firebreak and they last a really long time. Second, the high desert of the US is an active volcanic province. There are fresh basalt flows everywhere, some less than a thousand years old, in the terrain. It takes tens of thousands of years for these to support enough plant life to carry a burn. These natural barriers place limits on where they can go and how far they can get.
The desert does have fires but they tend to be muted and often self-limiting because large contiguous regions of dense fuel aren’t as common.