When we make our memories on trails and in wild places, they take on a kind of permanence and heft, long after we’ve packed up our tents and gone. In the first few months we dated, I took my wife camping among the sand dunes of Assateague Island National Seashore. In January. We might have been the only people there. Even the park’s wild horses wintered on the leeward side of the island. It was too windy for a fire, so we ate huddled behind a bush.