ACADIA NATIONAL PARK, Maine – Cheered by a key victory in Congress and good news from the Gulf oil spill zone, a relaxed President Barack Obama began a weekend holiday yesterday on a sun-dappled mountain peak overlooking the rocky Atlantic coast.Within hours of landing at the Bar Harbour airport in a smaller version of Air Force One, Obama, his wife Michelle and daughters Malia and Sasha were clambering over the granite outcrops at the summit of Cadillac Mountain in Acadia National Park. At 1 530 feet, it’s the tallest peak along the East Coast, according to the National Park Service.The family also went cycling for an hour on a secluded bike trail along a nearby lake.Their visit was scheduled to end tomorrow morning; no public events were planned.The brief vacation quickly yielded plenty of photos of a president.