Nearly half the town rents
A renters policy is inexpensive and covers belongings, liability and the cost of somewhere else to live. The landlord's policy does none of that for a tenant. Where ownership is barely over half, this is the gap that affects the most households by a wide margin.
Long-distance traffic, local consequences
An interstate this busy brings drivers from everywhere past local errands, and a meaningful share of them carry minimum limits or none. Arizona requires uninsured and underinsured motorist cover to be offered, and declining it is a decision worth revisiting on a road like this.
Older housing and a real winter
At this elevation pipes freeze, and older construction freezes sooner. A sudden burst is generally covered where a slow leak is not, and the clause that decides it usually turns on whether heat was maintained.