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CTU Identifier Codes

Date Issued: Approved by the Minnesota Governor's Council on Geographic Information 03/25/2009

Introduction: This standard provides a set of codes that uniquely identify more than 2700 cities, townships and unorganized territories (CTUs) within the state of Minnesota. These codes originate from the U.S. Geographic Names Information System and are recognized as a formal federal standard.

Applicability: Who cares about this standard? This standard is important to all developers of public databases containing information about cities, townships and unorganized territories in Minnesota.

When do they apply? When do they not apply? This standard has been developed to improve the exchange of public data about cities, townships and Census Bureau-defined unorganized territories. It is understood that some counties define unorganized territories differently than the Census Bureau. Such county-defined unorganized territories are not included within the scope of this standard. Use of this standard is mandatory when both of the following two conditions exist:

  • a state agency is transferring data to an external customer, AND
  • no other previously-agreed-to coding scheme for CTUs has been designated.

Use of this standard is recommended when local governments exchange data, or when any new public databases are being designed that incorporate a coding scheme for Minnesota cities, townships and/or unorganized territories. Use of this standard by organizations and individuals outside of state government is strongly encouraged, but voluntary. This standard applies to data that are being transferred, and does not attempt to restrict how those data are internally stored or used.

Purpose of this Standard: The purpose of this standard is to provide a single, common coding scheme to identify all cities, townships and Census Bureau-defined unorganized territories in Minnesota. It is intended to be used primarily when data are being transferred between a state agency and external customers. Its use will improve the sharing of data resources by avoiding unnecessary duplication and reducing incompatibilities in collecting, processing and disseminating data.

Standard Requirements: The city, township and unorganized territory identification codes that make up this standard comprise a subset of the federal Geographic Names Information System (GNIS). The GNIS is maintained by the U.S. Board on Geographic Names, U.S. Geological Survey, Department of the Interior. These GNIS feature identifier codes are also American National Standards Institute standards (ANSI INCITS 446:2008).

GNIS contains a nationally unique six- to eight-digit feature identifier code for each city, township and Census Bureau-defined unorganized territory in Minnesota and the nation. Within GNIS, cities and townships fall within the civil class of features. Census Bureau-defined unorganized territories fall within the Census class of features.

A complete list of GNIS feature identifier codes for CTUs in Minnesota with a crosswalk to legacy Census codes can be found at:

GNIS implements these codes as integers (e.g. City of Saint Cloud = 2396483).The U.S. Census Bureau implements the codes as eight character text codes with leading zeros included (e.g. City of Saint Cloud = 02396483). Each format may be useful for different purposes. Because both formats are so prominently used at the federal level, both of these formats are considered to be in compliance with this Minnesota state standard. The text-with-leading-zeros format is recommended for most purposes.

GNIS Feature ID codes are unique nationwide. However, at times a state or county code will be used in conjunction with these codes. This is typically done to identify the portions of a city that are split by multiple counties. In such a case, two existing State of Minnesota data standards are of use:

  1. Codes for the Identification of the States, and the District of Columbia
  2. Numeric Codes for the Identification of Counties in Minnesota

Used together, these three codes provide a unique identifier for all portions of cities that cross county boundaries (termed Minor Civil Divisions by the U.S. Census Bureau) For example, the City of Saint Cloud falls within the Counties of Benton, Sherburne and Stearns. Therefore, the Census unique identifier for that portion of St. Cloud within Benton County is 2700902396483. See the table below:

State Code County Code GNIS Feature ID Code for St Cloud Composite Code
27 009 02396483 2700902396483
27 141 02396483 2714102396483
27 145 02396483 2714502396483

Examples of GNIS feature identifier codes for CTUs

GNIS ID (Text Format) GNIS ID (Integer Format) CTU Name CTU Type
02394789 2394789 Forest Lake City
00664194 664194 Forest Lake Township (historical) Township
02394790 2394790 Foreston City
00664196 664196 Forest Prairie Township Township
00664197 664197 Forestville Township Township
02394797 2394797 Fort Ripley City
00664201 664201 Fort Ripley Township Township
00664202 664202 Fort Snelling (unorganized territory) Unorganized Territory
02394799 2394799 Fosston City
00664204 664204 Fossum Township Township

Compliance: What constitutes compliance? In cases where a state agency's databases include information about cities, townships and/or Census-defined unorganized territories, that agency must be capable of incorporating CTU codes in a form consistent with this standard (GNIS Feature ID in either text or integer format) for the purpose of exchanging data between organizations. Agencies may continue to structure and store data using alternate coding schemes as they see fit, provided the capability exists to readily output a format that complies with this standard if requested to do so by a customer. It is recommended that agencies integrate this standard into new database designs whenever possible.

How will compliance be measured? Evidence of compliance will be determined based on reports of satisfactory data transfers from receiving customers.

References and Sources of More Information: The U.S. Department of Interior, United States Geological Survey maintains the Geographic Names Information System (GNIS), which includes codes for a wide variety of geographic features.

The GNIS Feature Identifier Code, Official Feature Name, and Official Feature Location are American National Standards Institute standards as specified in ANSI INCITS 446-2008 (Identifying Attributes for Named Physical and Cultural Geographic Features (Except Roads and Highways) of the United States, Its Territories, Outlying Areas, and Freely Associated Areas, and the Waters of the Same to the Limit of the Twelve-Mile Statutory Zone). The standard is available at the ANSI Web Store.

A complete list of GNIS feature identifier codes for CTUs in Minnesota with a crosswalk to legacy Census codes can be found at:

The Metropolitan Council distributes a CTU code crosswalk table for the seven-county Twin Cities metropolitan area. The table includes many attributes related to CTUs including coding schemes currently or historically used by other organizations:


Further information about this standard may be obtained from the Minnesota Geospatial Information Office (MnGeo).

300 Centennial Building
658 Cedar Street
St. Paul, MN 55155

phone: 651-201-2499


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