Mudflats

A walk on Alaska's mudflats is no day at the beach.

"If you don't know what you're doing, they can be very dangerous," said Al Miners, superintendent of Chugach State Park near Anchorage, Alaska.

Besides mountains, forests and glaciers, Chugach State Park encompasses most of the tidelands beneath Turnagain Arm in upper Cook Inlet. A popular National Scenic Highway skirts the mudflats for about 40 miles from Anchorage to Portage. The byway is a favorite drive for vacationers, people destined for the many trailheads along its route, and wildlife watchers.

Many people come not for the outstanding scenery but for what lies beneath the inlet's choppy waters. Turnagain Arm is home to a pod of beluga whales. Others come to see the Arm's dramatic bore tide—a stunning showcase of water that comes into the Arm like a small tsunami, raising the water level by as much as 30 feet in a matter of minutes.

At low tide, the inlet is nearly void of water. The mudscape looks serene and solid. But don't be fooled. Sometimes the mudflats are like quicksand.

"They can swallow you up," Miners said.

Geologically, the mud in Turnagain Arm consists of fine silt particles, the end result of glaciers grinding away on the surrounding mountains. This silt, or glacial flour, is suspended by water droplets in the mud. That's what gives the mud its squishy feeling. But Miners warns that even mud which seems firm enough to support a person, may not be.

"If you go out there and stand in one place and wiggle your feet, you'll start to sink," he said. "Conversely, if you keep moving, you're less likely to have problems."

No one seems immune from getting stuck in Turnagain Arm's mudflats. Wind surfers, hikers, tourists and hunters all have become stuck and required help from emergency responders. Several years ago, one woman drowned after rescuers were unable to free her from the mud before the tide returned.

"It's legal to be out there, but the average person might think it's just a beach and go walking out there and get stuck," said Miners. "Then a 30-foot tide comes in and they're dead. That has, in fact, happened."

Park officials have placed warning signs in interpretive displays at popular turnouts and scenic points along the highway, in hopes of reducing the number of people who unknowingly flirt with disaster.

"Since then, we've not had any problems," said Miners.

Turnagain Arm in Cook Inlet isn't the only place with dangerous mudflats. People have become stuck in mudflats throughout Alaska. Wherever glaciers feed a river or delta, there is danger. Since glaciers feed most of Alaska's rivers, it's best to treat every mudflat with caution and respect, said Miners.