The proposed relationship of Leonard Washington Harvill as the father of Oren Elmer Harvill and Preston Oral Harvill is supported by DNA evidence indicating shared ancestry within the family lines.

Specifically, DNA evidence confirms a 2nd cousin, once removed relationship between JS (a descendant of the Oren Elmer Harvill ancestral line) and KM (a descendant of the Preston Oral Harvill ancestral line) with a shared segment of 108.82 cM across 5 HIR segments.

This match is consistent with their placement within these shared ancestral branches.