Is the fruit a double samara (a maple samara) with mostly 3 to 5 leaflets that are lobed or coarsely toothed, and with twigs green to purplish-green? It is a boxelder(Acer negundo), not a true elder.
Is the fruit a single-winged samara and the leaves have 5 to 13 (occasionally 3) leaflets? Clue: these are not native to Logan Canyon; only a few are found in developed areas in the lower part of the canyon. It is a green ash (Fraxinus pennsylvanica).