E. canadensis should have recurved awns (usually they would be visible by this late in the season),
spikes that look more slender and a lot of them slightly more gently nodding is less typical on E. canadensis.
many of the spikes losing all their seeds early is more typical of E. riparius than E. canadensis.
E. riparius or E. villosus. You may need to feel the leaf blades to check for pubescence to tell them apart. We are also one county out-of-range for both species.
However, the setting, bottomlands and presumably a floodplain, not far from a stream, would be good habitat for both species, especially E. riparius, and would be less good habitat for E. canadensis which on average is found in drier conditions, and is less tolerant of shade