Smithsonian trinomial facts for kids

Smithsonian trinomials are special codes used to name archaeological sites in many parts of the United States. These codes help archaeologists keep track of places where old things like tools, pottery, or ancient buildings are found.

Each code is usually made up of three parts:

• One or two numbers for the state.
• Two letters for the county (or a similar area) within that state.
• One or more numbers in order, showing when the site was listed in that county.

The Smithsonian Institution first created this system in the 1930s and 1940s. Back then, the 48 states were given numbers in alphabetical order. When Alaska became a state, it got number 49, and Hawaii got number 50. Washington D.C. and other U.S. territories do not use these numbers. Today, each state is in charge of giving out its own trinomial codes.

Most states use a code like "nnAAnnnn" (for example, "1AAnnnn" for Alabama). But some states add a space or a dash, like "nn AA nnnn" or "nn-AA-nnnn". Some states also have their own unique ways of using the system. For example:

• States like Arizona, California, Connecticut, Maine, Rhode Island, and Vermont use short two-letter names for their state instead of the Smithsonian number.
• Alaska uses three-letter codes from special maps (USGS map quadrangles) instead of county codes.
• Hawaii uses a four-part code that includes a number for the island and a number for a map section, along with the state number and site number.
• Connecticut and Rhode Island don't use county codes at all; their site codes are just the state abbreviation and a number for the whole state.

How States Label Ancient Sites

Here's a look at how different states use codes to identify archaeological sites: