First struck in 1948. Struck under the authority of the Director of the Mint (no congressional approval required) for a series of procurements by the Department of the Interior (DOI). Designed by Gilroy Roberts.
I recently added the gold
Distinguished Service to my herd. Slightly larger that a US
Morgan silver dollar.
Commendable Service in Bronze.
Meritorious Service in Silver.
Distinguished Service in Gold.

Reverse images coming...
However, I assigned identifiers to the medals in the DOI sGm series (as part of my ongoing research):
https://www.money.org/collector/drd...-version-2-0Note the second gold medal in the series!