Eva Grimes, a local historian, wrote the following:
Joseph Groat was among the early settlers of Sanilac County, Speaker Twp coming in 1860 from the London, Ontario area of Canada. He settled in the southern part of Elk Twp which would be near what is now the Village of Peck. With him came his wife, Sophia, and year old son Clark Groat. On December 31, a son Myron was born, the first white chid in Elk [T]wp. ["Joseph Groat," by Mrs Eva Grimes, p 180, HISTORY OF SANILAC COUNTY 1834-1984, ed Hazel Arnold Trumbel]

I have found a census record indicating that various members of the Vannest family were born in Peck and other parts nearby in Elk Twp, Sanilac Co, MI from the early 1850s to just before 1860, which would probably trounce Mr Groat's former record.

1860 > MICHIGAN > SANILAC > ELK
Series: M653 Roll: 558 Page: 1002
page no 164; 16 Jul 1860
lines 17-27
1289, 1233 Nathaniel Vannest 43m farmer $100 $300 Can
Matilda Vannest 39f Can
Calvin Vannest 17m Can
Mary Vannest 15f Can
Wealthy Vannest 13f Can
John Vannest 12m MI
Henry Vannest 9m MI
Charles Vannest 8m MI
Samuel Vannest 6m MI
Zelia Vannest 4f MI
Amanda Vannest 1f MI

I know that the Vannest family settled in Elk Twp because of local histories which state as much.

Meanwhile, some records related to Myron Henry Groat.

CENSUS
1870 US Census
series M593, roll 703, p 159, page no 2, lines 24-29
MI, Sanilac Co, Speaker Twp, 23 Jun 1870
16, 16 Grot Henry 35mw farmer $600 $200 Can
Sophia 35ff housekepper Can
Walter 11mw at school Can
Margaret 9mw MI [sic: Myron]
Ada 4fw Can
Berton 1mw MI

series T9, roll 1077, page 464, line 37
OH, Williams Co, Madison, 1880
* line 32, 6, 6, John Ashcroft wm75 father, farmer, 12 mo/yr empl, good health, PA PA PA
* line 37 Myron Groat wm 18 boarder, farmer, 12 mo/yr empl, good health, OH OH OH [sic: CanCanCan]

1900:
series T623, roll 743, p 314, sheet no 8B, lines 59-64
MI, Sanilac Co, Speaker Twp
ln 55 155, 155 Ketcher, Frank & family
156, 154. Myron Groat, head. w, m, Dec1860, 39yo, marr, 16ymarr. MICanEng. farmer. yes, yes, yes. OMF.
___ W [Olavine V]. Groat, wife. w, f, Dec1863, 36yo, marr, 16ymarr, 4chld, 4surv. CanCanCan. 1875, 25yUS. yes, yes, yes.
Floyd L, son. w, m, May1884, 12yo, sing, MI, MI, Can. @sch3mo, yes, yes, yes.
Orvil J.L., son. w, m, May1884, 13yo, sing, MI, MI, Can. @sch3mo, yes, yes, yes.
_lor_ On, son. w, m, Aug1888, 11yo, sing, MI, MI, Can. Asch3mo, yes, yes, yes.
Birddie, dtr, w, f, Dec1891, 8yo, sing, MI, MI, Can.
neighbours: 157, 155 Burton & Ida Groat. 158, 156 Arthur & Margerite A Billings. 153, 153 Kitchen? _lian, El_.

series T624, roll 675, p 26, page no 10A, lines 62-67
MI, Sanilac Co, Speaker Twp 06 May 1910
238, 240 Groat Myron H head mw 49 marr 25ymarr farmer general farm Empl OMF -yesyes
Olivine wife fw 46 marr 25ymarr 6 chld, 4 srv immig 1886 -yesyes
Claude M son mw 21 sing teacher district school -yesyes
Berdie E dtr fw sing -yesyes
Verna O dtr fw sing -yesyes
Lula F dtr fw sing-yesyes
neighbours: 237, 239 James & Mary Bomese(?); 232, 234 Justinian & Christiana Hilborn; 236, 238 Almanson (27yo) & Polly (26yo) Tibbits.

1920:
series T625, roll 797 p 1, lines 96-100
Speaker Township, Sanilac County, Michigan
Frm, 26, 27. Groat, Myron. Head. O, M. m, w, 59, marr. ---, yes, yes.
Groat, Ollie. Wife. ---. f, w, 56, marr. ---, yes, yes. Immig 1871, naturalised, naturalised 1881. Born in Canada. Father born in Canada, mother born in Canada.
Groat, Verna. Daughter. ---. f, w, 16, sing. yes, yes, yes.
Groat, Ly_t_ [Lula]. Daughter. ---. f, w, 13, sing. yes, yes, yes.
Groat, Russell. Grandson. ---. m, w, ---, sing. yes, yes, yes. Father born in Michigan, mother born in Micigan.
Neighbours: Frm, 25, 26 Head's mother Dutch. James & Mary Mulruey (?) both Irish descent. Frm, 23, 24. Byron & Nelly Joba. Scottish & Irish descents.

MARRIAGE
SANILAC COUNTY MARRIAGE INDEX 1849-1912
located at Sandusky District Library, Sandusky, MI
p 113, #357
Myron Henry Groat Elk teacher Speaker
Olvine Victoria Hilborn [sic: Olavine]
29 Aug 1883 H Andrews, Min; Alberta F Hilborn & Viola Hilborn, both of Speaker Twp, wit
see also Sanilac County Marriage Index 1880-1885 (located at Sandusky District Library)

DEATH
FLINT JOURNAL
Groat, Myron Henry
Flint Journal 16 Mar 1962
Man, 101, Dies; Sanilac Native
Myron Groat First County White Child
Myron H. Groat, 101, of [address] Torrey Rd., died Thursday at Stanmarie Nursing Home in Argentine.

Services will be at 2 p.m. Sunday in the Melvin Baptist Church. Burial will be in the Melvin Cemetery. The body is at the Carman Funeral Home, Brown City.

Mr. Groat was born Dec. 31, 1860, the first child born to white settlers in Sanilac County. He was born in a log cabin in Elk Township.

He had taught school, carried mail, and served as a jusgtice of the peace and farmed. He retired in 1934 after farming nearly 50 years.

His wife, Olivine, died in 1935. Mr. Groat lived in the Flint area the last 20 years.

He leaves a son, Claude, Eaton Rapids; three daughters, Mrs. Verna Harris, Flint; Mrs. Berdie Fletcher, Corvallis, OR, and Mrs. Lulu Wilhelmsen, Stillwell, OK; 24 grandchildren; 54 great-grandchildren, an five great-great grandchildren.
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Groat, Myron Henry
Flint newspaper poss 16 Mar 1962
Myron Henry Groat, of 6326 Torrey Rd, died at the age of 101 Thursday, March 15, 1962 at the Stan Marie Convalescent Home in Argentine, where he had resided since catching pneumonia in November. Funeral Services will be held at 2 p.m. Sunday, March 15, 1962 from the Melvin Baptist Church, Reverend John Trace officiating. Interment will be in the Melvin Cemetery. Mr. Groat may be seen at the Carmen Funeral Home in Brown City. He was born in Elk Township in 1860, the son of Joseph and Sophia Groat. Mr. Groat resided in Ohio for four years, then in Sanilac County for 76 years, and spent the past 20 years in Flint. He married Olivine Hilborn, who preceded him in death in 1935. Mr. Groat was a former farmer, mailman, and teacher. Surviving are his son, Claude Groat of East Rapids, three daughters, Mrs. Berdie Fletcher of Corvallis, Oregon, Mrs. Verna Harris of Flint, and Mrs Lulu Wilhelmsen of Stillwell, Oklahoma; 24 grandchildren, 54 great-grandchildren, and 5 great-great-grandchildren.

SANILAC COUNTY CEMETERY INDEX
Myron H Groat. b 1860. d 1962. Fairview Cem Sct B.

At this writing Les is living with a daughter in Avoca. He is 93 and likes to quote Myron Groat who at age 100 used to say, "You hardly ever hear tell of anybody my age dying." ["George Leslie 'Les' Collins," by Don L Collins, p 143, HISTORY OF SANILAC COUNTY 1834-1984, ed Hazel Arnold Trumbel]