Please join our ambitious efforts to protect Cook Inlet. Since 1995, Cook Inletkeeper has been working hard to protect water quality and salmon habitat so our families and communities can prosper from Alaska’s abundant resources. But we can’t do it without your support. Every penny counts. Please support Cook Inletkeeper today!
Turnagain Arm, the northeast arm of Cook Inlet is one of only about 60 bodies of water worldwide to exhibit a tidal bore. The bore may be more than six feet high and travel at 15 miles per hour on high spring tides.
Turnagain Arm sees the largest tidal range in United States, with a mean of 30 feet (9.2 m), and the fourth highest in the world, behind Bay of Fundy (38ft/11.7m), Ungava Bay (32ft/9.75m), and Bristol Channel (31.5ft/9.6m).