As the Seward Highway approaches Girdwood, travelers can see the remains of trees whose roots were swamped with salt water and killed during the 1964 Earthquake. Portage was devastated when much of the ground along Turnagain Arm sank five to nine feet. At high tide, the town that once lay at sea level was now under water. The ruins of buildings in the water are testament to that dramatic day the earth moved. Geologic evidence shows that four earlier earthquakes dropped the coastline here, just as the earthquake did in 1964. Past Girdwood, at an unmarked turnout, is evidence of another catastrophic seismic event in the area. A ghost forest older than the one that can be seen from the road rests partially buried in the silty banks of the Arm. It can only be seen at low tide by walking below the bank.
CAUTION! The mudflats of Turnagain Arm can be extremely dangerous. Travelers should not wander beyond the banks of the Arm. Fast-moving, incoming tides can liquefy the hard, silty ground. People have been trapped in the mud and drowned.