Search crews found "significant debris from the site, including all of the priority sensor and electronics pieces identified", said US Northern Command.
The FBI is examining the items, which the US says were used to spy on sensitive military sites.
The US has shot down three more objects since the first one on 4 February.บาคาร่าauto
"Large sections of the structure" were also recovered on Monday off the coast of South Carolina, military officials say.
About 30-40ft (9-12m) of the balloon's antenna are among the items found, according to CBS, the BBC's US partner.