A sick and starving orca that had been off the radar since last week was spotted near the west end of the Strait of Juan de Fuca on Tuesday evening.
Michael Milstein with NOAA Fisheries said J50 was seen with her mother, J16, which is a good sign.
Earlier Tuesday, federal officials had said they received legal permission to move forward with the treatment J50. The emergency plan is to inject the killer whale with antibiotics through a pole system from a boat.
Milstein said authorities are prepared to start action as soon as Wednesday if the whales continue moving toward the San Juan Islands.
NOAA would work with local tribes and governments to help feed J50. The plan calls for live salmon provided by the Lummi Nation.
The 3½-year-old was part of the southern resident "baby boom" that occurred when eleven calves were born between 2014-2016. Only five of the calves from the "baby boom" remain.