Ephraim G. Briggs died between 1852 and 1857.
I found the following mention of Ephraim G. Briggs in the Osage County Court Records- the court house was located in the town of Linn.
Some Misc Osage County, Court Records from the
Court House in Linn, Missouri
May 13, 1852
Road overseers which were appointed by the Court Included;
John Bacon, John King, Drewery Holland, Cooper, Thomas Cames, Henry Wolf,
Bernard Westerman, Joseph Tweehouse, Amelien Crutsinger,
George E.Bishop, Wm. Wolf: and John Calvin Briant.
Townships are being organized for the establishment of public schools.