There are idenfiable MSAs for the states of South Dakota and Wyoming in very small subset of IPUMS USA samples. Sioux Falls, SD is identified in 2005-2011 ACS samples, 2000 5%, and a few older samples. See this linkfor more details. Cheyenne, WY is identified in the 2003 ACS sample.
There are no identifiable MSAs for South Dakota or Wyoming in the 2012-2015 ACS samples. IPUMS USA creates the MET2013 codes by examining the relationship between Public Use Microdata Areas (PUMAs) and Metropolian Statistical Areas. For South Dakota and Wyoming, the PUMAs align poorly with the counties that comprise their MSAs; therefore, we are unable to identify the MSAs in the microdata. For more detail about how we create MET2013, please visit this link.