In 1910 a fossil hunter named Barnum Brown made news: He uncovered a cache of Albertosaurus fossils in the badlands of Alberta, Canada. It was extraordinary to find so many Albertosaurus skeletons together! Brown sent the bones to the Museum of Natural History in New York. There, they were eventually forgotten.

Almost 90 years later Philip Currie set out to find Brown’s dig site. Currie is a paleontologist, a scientist who studies fossils to learn more about the history of the Earth. First he searched the museum for clues and discovered four of Brown’s old photographs of the site and his field notes. Brown hadn’t written down the exact location—it was still a mystery.

Next Currie and his team of scientists rafted down the Red Deer River in Alberta, trying to match the scenery with landmarks in Brown’s photographs. One day the team discovered a hill that matched one in Brown’s photographs. The scientists were close! For hours the team searched the area in the blazing sun. The team was ready to give up; but Currie pushed on. On a ridge, he discovered the bone heap!