The Center for Whale Research said Tahlequah "vigorously chased a school of salmon with her pod-mates" when researchers spotted her on Saturday.
Whale experts say they have seen orcas mourn their offspring before, but J35 clung to her calf for an unusually long period of time.
The center said the whale appeared to be in good condition and "her behavior is remarkably frisky".
An audio recording from earlier this month apparently featured the mother's "mournful and prominent" calls, Q13 Fox reported.
After carrying her deceased baby for at least 17 days and 1,000 miles, an orca mother has shown signs of returning to normal.
A baby orca whale is seen being pushed by her mother July 24, 2018, after being born off the Canadian coast near Victoria, British Columbia. They hoped to capture the calf once Tahlequah finally let go, and discover why it had died - as almost all the babies in this pod seemed to. A scientist cried thinking of her. Tahlequah inspired politicians and essayists - and a sense of interspecies kinship in some mothers who had also lost children. The cause is no mystery: Humans have netted up the whales' salmon, driven ships through their hunting lanes and polluted their water, to the point that researchers fear Tahlequah's generation may be the last of her family.More news: Tiger Woods drawing biggest stir at PGA Championship
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Tahlequah is one of two orcas in the pod that scientists have been monitoring.
She finally abandoned the carcass as it decomposed, the AP reports.
There are only 75 southern resident killer whales - a distinct population of orcas that live in the northeast Pacific - and the group has not produced a surviving calf since 2015, meaning that they are at risk of dying out as they pass breeding age.
Scientists have also moved to save J-50, another whale in the endangered pod. The last successful birth was three years ago. But according to Mr. Garrett, the corpse most likely will never be found. But J35's mourning, which lasted at least 17 days, marks the longest such display ever documented among southern resident killer whales.
The chief culprit, researchers say, is there isn't enough salmon in the water to keep the orca population fit and healthy.