In 1910, the year after his discovery of (middle Cambrian) fossils in the Burgess shale, Walcott returned to the area accompanied by his sons Stuart and Sidney. Together they examined all the layers on the ridge above the point where the fossil-laden rock had been found, eventually finding the fossiliferous band. Between 1910 and 1924, Walcott returned repeatedly to collect more than 65,000 specimens from what is now known as the Walcott Quarry, named after him. The find includes exceptional preservation of the soft parts of its fossils, one of the oldest fossil beds containing soft-part imprints.