Exxon Valdez.: 20 years after the ecological disaster the oil is still there
The Exxon Valdez bleeding oil on 23rd March 1989

Three days ago it was the 20th anniversary of one of the worst environental disasters: the infamous oil spill of the Exxon Valdez in Alaska. Sadly experts say that two decades after that tragedy huge quantities of oil still coat Alaska's shores with a toxic glaze.

Of the 11 million gallons of crude oil that bled from the stranded tanker on the night of March 23, 1989, more than 21,000 remain, tucked into isolated coves and underneath the sand.

In its first toxic sweep, the Exxon Valdez oil spill killed about 250,000 seabirds, 4,000 sea otters, 250 bald eagles, and more than 20 orcas, according to the conservation group WWF.

Some images of the disaster from 20 years ago:
Exxon Valdez.: 20 years after the ecological disaster the oil is still there
Gray Whale Succumbs to Exxon Valdez Oil Spill, Latoucha Island, Alaska (John Gaps III / AP)

Exxon Valdez.: 20 years after the ecological disaster the oil is still there
The Exxon Valdez bleeding oil on 23rd March 1989

Exxon Valdez.: 20 years after the ecological disaster the oil is still there
The exxon Valdez towed away from the site of the ecological disaster

Exxon Valdez.: 20 years after the ecological disaster the oil is still there
A seabird covered with oil on on 23rd March 1989

Exxon Valdez.: 20 years after the ecological disaster the oil is still there
Crews use high-pressured hoses to blast oil-covered rocks on Naked Island, Alaska, on April 21, 1989, about a month after the Exxon Valdez tanker ran aground.
An 11,000-person crew removed much of the oil from the beaches until 1994, when government officials decided to end the clean-up effort.

The situation today:
As you can see in the images below, in the area hit by the oil spill, it's still very easy to find crude oil just below the superficial stones:
Exxon Valdez.: 20 years after the ecological disaster the oil is still there
Exxon Valdez.: 20 years after the ecological disaster the oil is still there
Exxon Valdez.: 20 years after the ecological disaster the oil is still there

Further info in this National Geographic article