These 87 rocks,one from each of Minnesota's counties, all carry an excerpt from a letter either to or from a deployed serviceman. The messages are a mix of sentimental and humorous, and but all are a reminder of the importance of the family at home to those deployed on active service. The letters from which the excerpts are drawn are from conflicts as far back as the Civil War and arrive up to date with communications from the Middle East.
They can be found on the Capitol Mall in Saint Paul,Minnesota very close to several other military memorials and the memorial to Minnesota peace officers killed in the line of duty. It was created in 2015 and was designed by landscape architect Ted Lee. It is said to be the first such tribute to military families in the USA.
Source: atlasobscura.com