My only (ha!) failing as a parent is that none of my children hikes, despite my best efforts to instill a proper love of the trail. Now that they’ve left the nest and are living out their drab, hike-free lives, there isn’t much I can do any more to rectify their urban existences. However, grandchildren are fair game. So, after a two-hour drive to the coast, made longer by the constant plaints of being hungry, cold, thirsty, bored, tired or all of the above, it was sweet vindication when grandchildren Aiden and Coral Marsh (ages 9 and 5, respectively) strolled …