If you start from the small parking lot on mills point road, it will be 5k one way to the break that Charles mentions. So a 10k round trip. If you park at the airport park, youll extend the route about a mile in each direction
I believe it is in the order of three miles long. However, there is gap may be half a mile from the northern side to let boats through. In the summer, there is ferry across the gap. The rest of the year, you can't travel the whole causeway.
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