Smithsonian trinomial

A Smithsonian trinomial (formally the Smithsonian Institution Trinomial System, abbreviated SITS)^[1][2] is a unique identifier assigned to archaeological sites in many states in the United States. Trinomials are composed of a one or two digit coding for the state, typically two letters coding for the county or county-equivalent within the state, and one or more sequential digits representing the order in which the site was listed in that county.^[3][4] The Smithsonian Institution developed the site number system in the 1930s and 1940s, but it no longer maintains the system. Trinomials are now assigned by the individual states. The 48 states then in the union were assigned numbers in alphabetical order. Alaska was assigned number 49 and Hawaii was assigned number 50, after those states were admitted to the union. There is no Smithsonian trinomial number assigned for the District of Columbia or any United States territory.^[5][6]

Most states use trinomials of the form "nnAAnnnn", but some specify a space or dash between parts of the identifier, i.e., "nn AA nnnn" or "nn-AA-nnnn". Some states use variations of the trinomial system. Arizona, California, Connecticut, Maine, Rhode Island, and Vermont use two-letter abbreviations of the state name instead of the Smithsonian number. Alaska uses three-letter abbreviations for USGS map quadrangles in place of the county code. Arizona uses a five-part identifier based on USGS maps, specifying quadrangles, then rectangles within a quadrangle, a sequential number within the rectangle, and a code identifying the agency issuing the sequential number. California uses a three-letter abbreviation for counties. Connecticut and Rhode Island do not use any sub-state codes, with site identifiers consisting of the state abbreviation and a sequential number series for the whole state. Delaware uses a single letter code for counties and adds a block code (A-K) within each county, with sequential numbers for each block. Hawaii uses a four-part identifier, "50" for the state, a two-digit code for the island, then a two-digit code to designate the USGS topographical quad, plus a four digit sequential site number for sites on each island.

Archaeological site identification codes used by states

State	Format	County or equivalent codes
Alabama	1AAnnnn[7]	AA: The code for a county is the first two letters in the county's name, with the following exceptions: Barbour=Br, Bibb=Bb, Blount=Bt, Bullock=Bk, Cherokee=Ce, Clinton=Cn, Choctaw=Cw, Clarke=Ck, Clay=Cy, Cleburne=Cb, Colbert=Ct, Conecuh=Cc, Coosa=Cs, Dallas=Ds, DeKalb=Dk, Elmore=Ee, Lamar=Lr, Lauderdale=Lu, Macon=Mc, Maringo=Mo, Marion=My, Marshall=Ms, Mobile=Mb, Monroe=Mn, Montgomery=Mt, Morgan=Mg, St. Clair=Sc, Tallapoosa=Tp, Washington=Wn, and Wilcox=Wx.[8]
Alaska	49‑AAA‑nnnn[9]	AAA: Three letter codes are abbreviations of the names for quadrangles on USGS maps for Alaska.[10]
Arizona	AZ AA:NN:nn(XXX)[11]	AA: One or two letter code, A through FF, identifying USGS map quadrangles (one degree of latitude by one degree of longitude) in Arizona. NN: One or two digit number, 1 though 16, identifying rectangles (15' USGS maps) in a quadrangle map.[12]
Arkansas	3AAnnnn	List of counties in Arkansas
California	CA‑AAA‑nnnn[13]	AAA: County Abbreviation Codes (Appendix 1)
Colorado	5AAnnnn[14]	AA: County Abbreviation Codes
Connecticut	CT‑nnnnn	No county code; state abbreviation and a sequential number only
Delaware	7ABnnnn[15]	A: K = Kent County, N = New Castle County, and S = Sussex County. B: Figure 25: Map of blocks
Florida	8AAnnnn[16]	AA: The code for a county is the first two letters in the county's name, with the following exceptions: Bay=BY, Bradford=BF, Broward=BD, Collier=CR, Gadsden=GD, Hardee=HR, Hendry=HN, Highlands=HG, Lafayette=LF, Lee=LL, Levy=LV, Madison=MD, Marion=MR, Martin=MT, Miami-Dade=DA, Okeechobee=OB, Palm Beach=PB, St. Johns=SJ, St. Lucie=SL, Santa Rosa=SR, Sarasota=SO, Sumter=SM, Walton=WL, and Washington=WS.[17]
Georgia	9AAnnnn[18]	AA: County Abbreviation Codes
Hawaii	50‑AA‑BB‑nnnn[19]	AA: 10 = Hawaii, 20 = Kaho'olawi, 30 = Kaua'i, 40 = Lana'i, 50 = Maui, 60 = Moloka'i, 80 = O'ahu, 91 = Necker, 92 = Nihoa[20] BB: USGS Quad number
Idaho	10AAnnnn	AA: Idaho County Abbreviations for Site Designation
Illinois	11AAnnnn[21]	List of counties in Illinois
Indiana	12AAnnnn[21]	List of counties in Indiana
Iowa	13AAnnnn[22]	AA: Iowa County Abbreviations for Site Designation
Kansas	14AAnnnn[23]	AA: Kansas County Abbreviations for Archeological Trinomials
Kentucky	15AAnnnn[21]	List of counties in Kentucky ADAIR (AD); ALLEN (AL); ANDERSON (AN); BALLARD (BA); BARREN (BN); BATH (BH); BELL (BL); BOONE (BE); BOURBON (BB); BOYD (BD); BOYLE (BO); BRACKEN (BK); BREATHITT (BR); BRECKINRIDGE (BC); BULLITT (BU); BUTLER (BT); CALDWELL (CA); CALLOWAY (CW); CAMPBELL (CP); CARLISLE (CE); CARROLL (CL); CARTER (CR); CASEY (CS); CHRISTIAN (CH); CLARK (CK); CLAY (CY); CLINTON (CT); CRITTENDEN (CN); CUMBERLAND (CU); DAVIESS (DA); EDMONSON (ED); ELLIOTT (EL); ESTILL (ES); FAYETTE (FA); FLEMING (FL); FLOYD (FD); FRANKLIN (FR); FULTON (FU); GALLATIN (GA); GARRARD (GD); GRANT (GR); GRAVES (GV); GRAYSON (GY); GREEN (GN); GREENUP (GP); HANCOCK (HA); HARDIN (HD); HARLAN (HL); HARRISON (HR); HART (HT); HENDERSON (HE); HENRY (HY); HICKMAN (HI); HOPKINS (HK); JACKSON (JA); JEFFERSON (JF); JESSAMINE (JS); JOHNSON (JO); KENTON (KE); KNOTT (KT); KNOX (KX); LARUE (LU); LAUREL (LL); LAWRENCE (LA); LEE (LE); LESLIE (LS); LETCHER (LR); LEWIS (LW); LINCOLN (LI); LIVINGSTON (LV); LOGAN (LO); LYON (LY); MCCRACKEN (MCN); MCCREARY (MCY); MCLEAN (MCL); MADISON (MA); MAGOFFIN (MG); MARION (MN); MARSHALL (ML); MARTIN (MT); MASON (MS); MEADE (MD); MENIFEE (MF); MERCER (ME); METCALFE (MC); MONROE (MR); MONTGOMERY (MM); MORGAN (MO); MUHLENBERG (MU); NELSON (NE); NICHOLAS (NI); OHIO (OH); OLDHAM (OL); OWEN (ON); OWSLEY (OW); PENDLETON (PD); PERRY (PE); PIKE (PI); POWELL (PO); PULASKI (PU); ROBERTSON (RB); ROCKCASTLE (RK); ROWAN (RO); RUSSELL (RU); SCOTT (SC); SHELBY (SH); SIMPSON (SI); SPENCER (SP); TAYLOR (TA); TODD (TO); TRIGG (TR); TRIMBLE (TM); UNION (UN); WARREN (WA); WASHINGTON (WS); WAYNE (WN); WEBSTER (WE); WHITLEY (WH); WOLFE (WO); WOODFORD (WD)
Louisiana	16AAnnnn[24]	List of parishes in Louisiana
Maine	ME-nn-nn
Maryland	18AAnnnn[25]	List of counties in Maryland
Massachusetts	19-AA-nnnn
Michigan	20AAnnnn[26]	List of counties in Michigan
Minnesota	21AAnnnn[27]	AA: Trinomial Site Designations for MN Counties
Mississippi	22‑AA‑nnnn[28]	List of counties in Mississippi
Missouri	23AAnnnn	List of counties in Missouri
Montana	24AAnnnn[29]	AA: Trinomial Site Designations for MT Counties
Nebraska	25AAnnnn[30]
Nevada	26AAnnnn[31]
New Hampshire	27‑AA‑nnnn[32]	AA: Belknap (BK) · Carroll (CA) · Cheshire (CH) · Coos (CO) · Grafton (GR) · Hillsborough (HB) · Merrimack (MR) · Rockingham (RK) · Strafford (ST) · Sullivan (SU)
New Jersey	28AAnnnn
New Mexico	29AAnnnn
North Carolina[33]	31AAnnnn	List of counties in North Carolina AA: Alamance (AM) · Alexander (AX) · Alleghany (AL) · Anson (AN) · Ashe (AH) · Avery (Av) · Beaufort (BF) · Bertie (BR) · Bladen (BL) · Brunswick (BW) · Buncombe (BN) · Burke (BK) · Cabarrus (CA) · Caldwell (CW) · Camden (CM) · Carteret (CR) · Caswell (CS) · Catawba (CT) · Chatham (CH) · Cherokee (CE) · Chowan (CO) · Clay (CY) · Cleveland (CL) · Columbus (CB) · Craven (CV) · Cumberland (CD) · Currituck (CK) · Dare (DR) · Davidson (DV) · Davie (DE) · Duplin (DP) · Durham (DH) · Edgecombe (ED) · Forsyth (FY) · Franklin (FK) · Gaston (GS) · Gates (GA) · Graham (GH) · Granville (GV) · Greene (GR) · Guilford (GF) · Halifax (HX) · Harnett (HT) · Haywood (HW) · Henderson (HN) · Hertford (HF) · Hoke (HK) · Hyde (HY) · Iredell (ID) · Jackson (JK) · Johnston (JT) · Jones (JN) · Lee (LE) · Lenoir (LR) · Lincoln (LN) · Macon (MA) · Madison (MD) · Martin (MT) · McDowell (MC) · Mecklenburg (MK) · Mitchell (ML) · Montgomery (MG) · Moore (MR) · Nash (NS) · New Hanover (NH) · Northampton (NP) · Onslow (ON) · Orange (OR) · Pamlico (PM) · Pasquotank (PK) · Pender (PD) · Perquimans (PQ) · Person (PR) · Pitt (PT) · Polk (PL) · Randolph (RD) · Richmond (RH) · Robeson (RB) · Rockingham (RK) · Rowan (RW) · Rutherford (RF) · Sampson (SP) · Scotland (SC) · Stanly (ST) · Stokes (SK) · Surry (SR) · Swain (SW) · Transylvania (TV) · Tyrrell (TY) · Union (UN) · Vance (VN) · Wake (WA) · Warren (WR) · Washington (WH) · Watauga (WT) · Wayne (WY) · Wilkes (WK) · Wilson (WL) · Yadkin (YD) · Yancey (YC)
North Dakota	32AAnnnn[34]	AA: NDCRS Site Form Training Manual - Section I: Site Identification - County Codes (Page 10)
Ohio	33‑AA‑nnnn[35]	AA: Appendix B: County Codes (OAI Codes) (Page 61)
Oklahoma	34AAnnnn[36]	AA: Table 1
Oregon[37]	35‑AA‑nnnn	List of counties in Oregon
Pennsylvania[38]	36‑AA‑nnnn	List of counties in Pennsylvania
Rhode Island	RI‑nnnn	No county code; state abbreviation and a sequential number only
South Carolina	38‑AA‑nnnn[39]	List of counties in South Carolina AA: Abbeville (AB) · Aiken (AK) · Allendale (AL) · Anderson (AN) · Bamberg (BA) · Barnwell (BR) · Beaufort (BU) · Berkeley (BK) · Calhoun (CL) · Charleston (CH) · Cherokee (CK) · Chester (CS) · Chesterfield (CT) · Clarendon (CR) · Colleton (CN) · Darlington (DA) · Dillon (DN) · Dorchester (DR) · Edgefield (ED) · Fairfield (FA) · Florence (FL) · Georgetown (GE) · Greenville (GV) · Greenwood (GN) · Hampton (HA) · Horry (HR) · Jasper (JA) · Kershaw (KE) · Lancaster (LA) · Laurens (LU) · Lee (LE) · Lexington (LX) · Marion (MA) · Marlboro (ML) · McCormick (MC) · Newberry (NB) · Oconee (OC) · Orangeburg (OR) · Pickens (PK) · Richland (RD) · Saluda (SA) · Spartanburg (SP) · Sumter (SU) · Union (UN) · Williamsburg (WG) · York (YK)
South Dakota	39AAnnnn[40]
Tennessee[41]	40AAnnnn	AA: County Abbreviations for Archaeological Site Numbers
Texas[42]	41‑AA‑nnnn	AA: Texas County Abbreviations
Utah[43]	42‑AA‑nnnn	AA: List of counties in Utah (p. 3)
Vermont[44]	VT‑AA‑nnnn	AA: Addison (AD) · Bennington (BE) · Caledonia (CA) · Chittenden (CH) · Essex (ES) · Franklin (FR) · Grand Isle (GI) · Lamoille (LA) · Orange (OR) · Orleans (OL) · Rutland (RU) · Washington (WA) · Windham (WD) · Windsor (WN)
Virginia[45]	44-AA-nnnn	List of county and city abbreviations in Virginia
Washington[46]	45‑AA‑nnnn	List of counties in Washington
West Virginia[47]	46‑AA‑nnnn	List of counties in West Virginia
Wisconsin[48]	47‑AA‑nnnn	List of counties in Wisconsin
Wyoming[49]	48AAnnnn	List of counties in Wyoming and also YE for sites within Yellowstone National Park