Marine scientists from both sides of the border say they gathered their most successful research ever on southern resident killer whales last month.
Researchers from Canada and the U.S. spent three weeks following roaming pods on the west coast of the two countries and were surprised to find the newborn.
The orca calf was seen about 15 miles west of Westport, Washington.
The group said they collected more data last month than they have on the eight previous trips dating back to 2004.
"There was so much great data that will really help us move forward in our comprehensive recovery program for the southern resident killer whales," said Lynne Barre, a marine biologist at NOAA.
There are about 80 southern resident killer whales left in the world and they've been on the endangered species list since 2005, according to NOAA.
The southern population spend their summers in the waters around southern Vancouver Island and northern Washington, but can travel much farther in the winter.