Where America built its towers — what the density figures show

Raw counts of infrastructure mostly measure population. Texas has the most registered antenna structures of any state; Texas also has a great many people. That comparison is not interesting.

Density is interesting, and it produces a completely different ordering.

Two rankings, two stories

By total structures, the leaders are the large-population states: Texas, California, Florida, Ohio, Georgia. Nothing surprising.

By structures per 100,000 residents, the leaders are Alaska, North Dakota and Mississippi. California falls to the bottom third.

Alaska has roughly twelve times the per-capita structure density of California. That is not a statement about how well-served Alaskans are. It is a statement about geography.

Why sparse places need more structures per person

Coverage is a function of area, not of population. A tower serves a radius, and the number of people inside that radius depends entirely on how densely they live.

Serving 700,000 people spread over 1.5 million square kilometres of Alaska requires a great many sites, each serving very few people. Serving 700,000 people in a dense Californian city requires fewer structures — and much of that city’s capacity comes from small cells and rooftops that never enter the register at all.

So the per-capita figure is measuring two things at once: how spread out the population is, and how much of the local infrastructure happens to be tall enough to register.

The registration threshold distorts the comparison

This is the part that requires care.

Only structures over about 200 feet — or shorter ones near airports — must register. In rural areas, where a single site covers a wide area, sites need to be tall, and tall means registered. In cities, a great deal of coverage comes from equipment 6 to 12 metres up on utility poles, which never appears.

The consequence: the register captures a much larger share of real infrastructure in rural areas than in urban ones. Rural density is close to complete; urban density is substantially understated.

Which means the Alaska-versus-California gap is real but overstated. Some of it is genuine geography. Some of it is a measurement artefact.

We say this on the pages themselves rather than presenting the ranking as though it were a coverage league table.

What the figures do support

Comparison between similar places. Two mid-sized cities in the same region, with similar building patterns, are comparable. The threshold effect applies about equally to both.

Comparison over time within a place. The build-out pattern by decade shows when a region’s infrastructure went in, and that is not distorted by the threshold.

Ownership concentration. Which companies own the vertical infrastructure in a state is accurately represented regardless of what is missing.

Identifying genuinely thin coverage. A rural county with very few registered structures probably does have poor coverage, because in rural areas registered structures are most of the story.

What they do not support

“State A has better coverage than State B.” The register measures structures, not coverage, and undercounts urban infrastructure specifically.

“This city is underserved.” A city with low registered density may be extremely well served by small cells. You cannot tell from here.

Anything about capacity. A single modern site can carry many times the traffic of an older one. Counting structures counts steel, not throughput.

Reading the state pages

Each state page shows total structures, per-capita density, median height and the largest owners. The most informative of these is usually median height, which varies more than you would expect and says something real about what kind of infrastructure a state has: tall guyed broadcast masts in the flat middle of the country, shorter urban monopoles on the coasts.

The full state table sorts by count, with density alongside. Sorting your eye down the density column instead is a different and more revealing read.