This elderly dog was found in O’Fallon, MO. For reasons unknown, he was taken to a shelter/rescue organization 30 miles away in House Springs, MO.
The following is the post from the Good Samaritan who found the dog:
A community member who lives in the area where the dog was found hung found dog signs in the area, as well as posted the dog on NextDoor.com, which is a great free resource to communicate with area residents.
Below shows the communication from a neighbor who owns this dog.
Below is the update from the neighbor whose keen eye helped the elderly dog and owner to be reunited. 
For those that are St Charles County residents, you have a wonderful resource at your fingertips for found animals! Animals found during ‘after hours’ of when our area shelters are closed can be taken to the following location. The clinic will scan the found pet for a microchip, and if one is found, the owner will be contacted. The pet will be transferred to the St Charles County or St Charles City shelter, based upon jurisdiction of where the pet was found, which is a fantastic arrangement for our county. The shelter is where owners will go in search of their missing pet!
Animal Emergency Clinic O’Fallon