The Largest County in Every State by Property Records

Every state has one county file larger than the rest. This report names that county for each of the 50 states and the District of Columbia in the October 2026 edition of the county index, sets its record count against the state’s total, and measures how far it leads the state’s second-largest county.

Taken together, these 51 counties hold 21,848,832 property records, 16.7% of everything in the index. The largest of them is Los Angeles County, the top county in California, with 2,275,994 records. The smallest is Laramie County, which leads Wyoming with 45,018. The biggest leader has 51 times as many records as the smallest, though each is the largest file in its own state.

Records in these 51 counties

21,848,832

Share of the index

16.7%

States where one county holds over half

4

Also in the national top 25

11

Where one county dominates

The share column is the clearest measure of dominance. In 4 states with more than one county, the largest county holds more than half of all the state’s records: Nevada, Hawaii, Arizona and Rhode Island. In those states, one file is most of the market. The highest share belongs to Clark County in Nevada, at 67.8%.

Figure 1 groups all 51 by that share. The 100% column holds the one jurisdiction filed as a single county-level area, the District of Columbia, where the largest county is the whole of it by definition. At the opposite end, in 8 states, even the largest county holds less than a tenth of the state’s records, so no single file goes far towards covering the state.

A high share tends to reflect one of two situations. Either the state has a single large metropolitan county and a rural remainder, or it has few counties to begin with, so each one carries a large part of the total. The county column in Table 1 helps tell them apart: a high share in a state with dozens of counties is the first case, a high share in a state with a handful is often the second.

How far the leader is ahead

Share measures the leader against the whole state; the lead column measures it against its nearest rival. The widest lead is in Illinois, where Cook County holds 5.6 times as many records as DuPage County. The narrowest is in Connecticut, where Greater Bridgeport Planning Region County is ahead of Capitol Planning Region County by a factor of 1.00. In 22 states the leader is less than 25% larger than the runner-up, close enough that the order could change between monthly editions.

A narrow lead says that a state has two comparable centres of property rather than one. For a buyer that often means the first two files in the state are worth considering together, since neither one alone covers the state’s largest concentration of records.

Leaders by national standards

Being the largest county in a state does not make a file large by national standards. Of these 51 counties, 11 also rank among the 25 largest county files in the country; the rest are first in their state but further down the national list. Some states’ second- or third-largest counties hold more records than other states’ leaders, which is why this table and the national ranking of the largest county files list different counties.

The bottom of Table 1 shows the other side. The 5 smallest leaders, in South Dakota, Montana, North Dakota, Vermont and Wyoming, hold between 45,018 and 71,930 records each, yet on average each holds 17.5% of its own state’s records. A small leader is not necessarily a weak one: in a state with little property overall, the top file can still be a large part of the market.

Buying the leaders

Because each county is sold separately, the leaders can be bought on their own. All 51 together would cost $509 a month at current prices, using the cheapest mix of $19/mo single counties and five-county bundles at $49/mo. A buyer working one region needs only the leaders of the states in it, and the share column says how much of each state that one file reaches. Where the share is low, the state page lists every county with its record count, which is the place to pick the next files to add.

Method

For each state, counties are ranked by property records in the October 2026 edition, with ties broken alphabetically, and the first is reported. Share of state is that county’s records divided by the state’s total. The lead is its records divided by the second-ranked county’s. All figures are recalculated daily from the county index. For state totals and the smallest county in each state, see property records by state.

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