Newly released results indicate the basket dates between A.D. 690 and 970, making it a rare find.
Tests also confirmed the whitish crystals that were found inside were salt, officials said. Tests were still underway to determine the origin of the salt.
Once testing is done, the basket will become part of the collection at the Museum of New Mexico.
The hikers found the partially buried basket during an outing in northwest Socorro County in January 2009, the Bureau of Land Management said. It was tucked under a rock overhang.
Carol Chamberland, one of the hikers and a BLM volunteer, suggested the group report the find to the BLM. They did, and a team of two archaeologists and a law enforcement agent was quickly assembled to recover the basket.
After being led to the site by hiker Larry Flinn, the team carefully removed the basket and prepped it for transport to the Museum of New Mexico's lab in Santa Fe.
"A piece of New Mexico's cultural history is now preserved thanks to the group of hikers who originally found the basket and knew to do the right thing," the agency said in a statement. "Because of their actions, the basket has already provided important scientific information and has been preserved to be enjoyed by others.
The basket was only recently preserved and dated.
Its age was not initially known since officials said its style is common and not unique to any particular time period or culture.
"We hope the basket will be on public display in the near future," the BLM said. "A location with controls for humidity, temperature and light will be required, as exposure would cause it to deteriorate."