Until this week, the trail on Harriet went cold after the death of her husband, Alexander Stuart McGinnis. He died in Coshocton County, Ohio, in 1897. Harriet is found still living there in the 1900 Federal Census. It seemed likely that she also passed away between the 1900 and 1910 Federal Census, but I could find no records of such. So I put the issue aside for awhile.
One of the many new places I have looked for resources and help has been various genealogy related groups with Facebook Pages. I joined several of these groups in recent months:
Genealogy: Lost and Found
St. Louis Genealogical Society
Missouri Genealogy Network
Colorize Old Pictures
Your Genealogy Brick Walls
Genealogy and Historical Databases
US Gen Web Project
Random Acts of Genealogical Kindness
It was in this last Facebook group that I posted a note looking for help on finding Harriet and Alexander's burial place and Harriet's death record at 11:30 PM night before last.
The response to my request was impressive. Almost 17,000 people belong to this group and some are very knowledgeable. Lucky for me, a couple of those folks grabbed the issue. I got responses including links to newspaper articles with both of their obituaries, links to records of Alexander's death of pneumonia and his burial at Union Cemetery in Coshocton County, a copy of a newspaper article reporting Harriet's death of old age in 1904 at the county Asylum. I quickly ordered both obituaries from the Coshocton County library.
It turns out that both Tunnel Hill and Smith's Hill are now both part of Union Cemetery where their son Walter is also buried.
The whole process took less than an hour. I was, and still am, amazed and very grateful.