Ashley Ahearn

Two dams blocked the river for more than 100 years. The lower dam is completely gone and the last 30 feet of the upper dam were blown up this week. Now, the river is returning to life.

Earlier this month, China imposed a ban on shellfish imports from most of the U.S. West Coast after finding two bad clams. The move is hitting Washington state particularly hard. State agencies estimate businesses there are losing as much as $600,000 a week.

The Cascades frog used to occupy alpine zones from California to the Canadian border, but its range is shrinking as global temperatures increase and snowpack declines. Scientists are hiking deep into the mountains of the Northwest to study the tiny frog, which makes a call that has been described as a "chuckling" sound.

Scientists are worried about the elusive members of the weasel family that live in parts of Olympic National Forest in Washington state. To see whether martens are endangered, volunteers are installing remote camera traps to take photos of the animals.

The U.S. Navy is in the process of renewing its permits to conduct sonar and explosive tests off the coast of the Pacific Northwest. But the recent unexplained death of a young orca who washed ashore in February has thrown a wrench in the process. Experts say injuries to the whale may indicate she was exposed to an underwater explosion or sonar testing.

Scientists with the National Oceanic and Atmospheric Administration are working to prevent outbreaks by tracking when and where red tide in Puget Sound will happen next.

Debris from the tsunami that hit Japan last March is just now starting to show up on the far northwestern shores of the U.S. Some fishermen are worried the floats and other rubble may tangle their nets and affect their livelihood. Ashley Ahearn of the public media collaboration EarthFix headed out to Washington State's Olympic Peninsula to see what's coming ashore.

Scientists aren't sure what's wrong with the orcas in Puget Sound, but they're hot on the trail. A team of researchers is relying on a secret weapon with a killer nose to sniff out the mystery.