Who owns America's cell towers

If you look up a structure near you and find it registered to something called CCATT LLC, you have run into the single most confusing thing about American communications infrastructure: the companies that own the towers are mostly not the companies whose networks run on them.

The split

Across the 141,542 constructed structures currently on the federal register, ownership breaks down roughly like this:

Owner type	Share of structures
Tower companies	about 52%
Carriers	about 11%
Government	about 7%
Broadcasters	about 4%
Utilities	about 4%
Railroads	about 1.5%
Everyone else	about 19%

The single largest owner is American Towers LLC, with more than 17,000 registered structures. That is more than any carrier owns directly.

How it got that way

Until the late 1990s, carriers built and owned their own towers. Each network put up its own steel, which meant three or four masts serving the same junction — expensive for the carriers and unpopular with everyone who had to look at them.

The economics were also poor. A tower is a long-lived, capital-intensive asset that earns rent. A mobile network is a fast-moving, technology-driven business that needs capital for spectrum and equipment. Those are different businesses with different investors, and through the 2000s the carriers progressively sold their towers to companies set up specifically to own them, then leased back the space.

Most of the big tower owners are now structured as real estate investment trusts. That is the correct way to think about them: they are landlords whose properties happen to be vertical.

Why one tower serves several networks

A tower company’s incentive is to put as many tenants on each structure as possible. The marginal cost of a second carrier on an existing tower is small; the marginal revenue is large. That is the entire business model, and it is why co-location is now the norm rather than the exception.

It is also why the structure database cannot tell you whose network you are on. One mast may carry equipment from three carriers, a public safety network and a couple of wireless internet providers. The registration records one owner: the landlord.

The naming problem

Tower company registrations are held by a sprawl of subsidiaries whose names contain no hint of the parent. A partial list:

• Crown Castle appears as CCATT LLC, Crown Atlantic Company LLC, Crown Communication LLC and Pinnacle Towers LLC, among others
• Vertical Bridge appears as VB-S1 Assets LLC, VB BTS III LLC, VB Nimbus LLC
• Verizon appears as Cellco Partnership, and as various regional SMSA limited partnerships
• AT&T appears as New Cingular Wireless and SBC Tower Holdings
• T-Mobile appears as STC entities, Omnipoint and Powertel, remnants of acquisitions

This is not obfuscation. It is the residue of decades of mergers, portfolio sales and financing structures, each of which left its own legal entity behind. But it does mean that counting towers by the owner name in the raw file gives a badly distorted picture of market concentration.

This site groups the entities it recognises, which is why the ownership breakdowns on our state and city pages differ from what you would get by grouping the raw field directly. Where we cannot confidently attribute a subsidiary, we leave it unattributed rather than guess.

The independents

Below the four large tower REITs sits a long tail of regional and independent owners — companies with a few hundred structures in one or two states, often built to serve a specific carrier contract and retained afterwards. There are more than 22,000 distinct registered owners in total, and the great majority of them own exactly one structure.

Those single-structure owners are worth noticing. They are farmers with a mast on a hill, small radio stations, county emergency services, irrigation districts, ski resorts. American communications infrastructure has a very long tail, and the federal register is one of the few places you can see it.

What this means when you look something up

Three practical consequences:

The owner name does not tell you your carrier. There is no field in the ASR data that does. If you need to know which network serves an address, the carriers’ own coverage maps are the tool, imperfect as they are.

A tower company owner suggests multiple tenants. It is not a guarantee, but a structure owned by American Tower or Crown Castle is far more likely to carry several networks than one owned by a county sheriff’s department.

An unusual owner is usually the interesting story. A structure registered to a railway, a utility or a school district is being used for that organisation’s own operations, not for public mobile service. Those are often the most interesting entries in any local list.