The Port of Hood River says the Hood River-White Salmon Interstate bridge will be closed to all traffic for a 72-hour period beginning at 12:01 a.m. June 10 through 11:59 p.m. June 12 to allow crews to repave the Oregon and Washington approach ramps.  Consulting engineer Harvey Coffman of Coffman Engineering says the ramps were originally constructed in 1951 and they are showing their age, as evidenced by the development of potholes and increased patching on the roadway surface, plus ruts are staring to be created and recent testing identified chloride infiltration in the concrete surface that if left untreated, can accelerate corrosion of the reinforcing bars that can lead to increased deterioration.  Port Executive Director Michael McElwee said the work will be done around the clock, with the shortest possible closure duration and was planned for a weekend to lessen the impact on businesses and commuters.  He did say they did not anticipate the hardship the closure would cause for families celebrating high school graduations in the area, adding regret for the additional travel time that may be required for those families.  Since the work must be conducted in dry conditions, it will be rescheduled if the weather is rainy, with an alternate work window of June 24-26.