Our first thought was blackberry, but the rest of the bush doesn't quite match up. For one, there are no thorns on the branches. The leaves are also roughly palm-sized, shiny, and scalloped. Also, we'd definitely say this more of a tree than a bush. Willow-thin branches arched far above our head, all seeming to come from a central source.
We did some comparisons of the berries and leaves online, and we're 99% sure we know what this is. If we're right, we can't wait to run back and pick all the berries we can find! But before we reveal our guess, we'd love to hear yours. What do you think this berry is? Update! Yes! Mulberries it is! Thanks for the confirmation, everyone. We're off to gather our berries while we may and read through your suggestions for what to do with them... Related: Found Food: Do You Forage for Food? (Images: Emma Christensen for the Kitchn)