Another struggling female in the same pod - J50, also known as Scarlet - was shot with antibiotics to fight an infection, since scientists worry that she has been losing a frightening amount of weight.
The Center for Whale Research has confirmed that the mother's "tour of grief" is finally over.
The calf died soon after birth in July, and the orca mom had carried the body for almost three weeks while traveling hundreds of miles.
The Center for Whale Research in Washington state says it watched the orca, known as Tahlequah or J35, chase a school of salmon in Haro Strait west of San Juan Island on Saturday afternoon. But the bonds between mothers and calves are extremely strong.
Exacerbating the problem is that orcas do not have babies often or in large numbers, and when they do, it is a long process.
"Her tour of grief is now over and her behavior is remarkably frisky".
"Telephoto digital images taken from shore show that this mother whale appears to be in good physical condition", CWR said in a statement on Saturday.
Deborah Giles, a research scientist and research director for nonprofit Wild Orca, said watching the orca with her calf was emotionally draining.
The centre called the mother's ordeal "record-setting". "Now we can confirm that she definitely has abandoned it".
Whale J35 seen here supporting her dead calf.
More than two weeks after the death of her baby, a grieving orca whale has released her dead calf's body after carrying it around the Pacific Northwest's waters.
The centre says the carcass likely sank to the bottom of the Salish Sea, and researchers may not get a chance to perform a necropsy.