Here is a restored version of a map from 1910 that appeared in Hamptons magazine. It has not been seen in print in 90 years. Teams went ahead and built camps. Igloos were constructed and waiting for Matt and Peary when they came along.
Igloos are warmer than tents in the Arctic.
Supplies were brought up from the reserve supplies at the land camp called Crane City. In fact Peary needed extra fuel for the stoves so Marvin made a special trip back for more. After each team had served their purpose by hauling supplies, making the trail and building igloos they were sent back. It is very dangerous on the Polar Ocean. Once Borup's sled started to slide into ocean, his dogs were in the water but he was an athlete, from Yale, and was strong enough to pull the sled back and save his dogs.