On February 23, 2003 two Trumpeter Swans with neck bands were seen on the south side of Carter Lake, which would be the Carter Lake, Pottawattamie County, Iowa portion of the oxbow lake of the Missouri River.
The markings on the red neck bands were J50 and J84.
Once these details were obvious, an email was sent to Dave Hoffman, a wildlife technician with the Iowa Department of Natural Resources. He provided the following details which indicated that at least two of the five swans present were from Iowa.
J50 was 2000 hatch year male from Beemer's pond (five miles west of Webster City, Iowa). He was released at Crawford Creek (Ida Co.), three miles south of Battle Creek, (Ida county, Iowa) on May 18, 2001.
This bird had also been previously seen January 27, 2002 at County Highway A and 144th St. five miles west of Kearney (Clay county), Missouri.
J84 was a 2000 hatch year female from Rick Stickle's (Kirkwood Community College) in Cedar Rapids, Iowa. She was released at Princeton WMA, two miles north of Princeton (Scott county), Iowa on April 11, 2001.
These details suggest that when Trumpeter Swans occurred in early-January through early-March in 2013, the birds may have been from places in Iowa.
In 1995 the Iowa Department of Natural Resources initiated a trumpeter swan restoration project in the state with the release of ten trumpeters near Spirit Lake in northwest Iowa, Hoffman said.
These records from my bird archive indicate the effort was an obvious success a decade ago, and appreciated on the west side of the Missouri River. Then and now!