Any idea on why these two sections of grading aren't connected with some sort of grading? It doesn't really make sense for the graders to build a grade, skip a quarter of a mile, and then resume.
A few possibilities come to mind:
1 - Both graded sections traverse hardwood swampland. Between them is an abandoned farm field. Could be grading across the field was delayed waiting for a crop harvest and the RN&P folded in the interim?
2 - The area between the gradings is essentially level - the elevation just a foot or two higher than the adjacent gradings. Perhaps the plan was to simply lay ties/rails directly on the ground here? Would make sense since the RN&P was cash-strapped throughout its brief existence.
3 - It's likely grading was performed in short sections; each section by a different contractor. Likely also many (all?) of the "contractors" were farmers whose land the ROW crossed. (The nearby Genesee Valley canal was dug this way) . More aggressive and energetic contractors might have completed rough grading of their section before the contractor on an adjacent section moved a shovelful of dirt.
Just guesses however....