Iron ore shipments traveling from Minnesota across the Great Lakes-St. Lawrence Seaway are at the highest level they have been in a decade, officials said.

The biggest contributors are Canada's largest ship operator, Algoma Central Corp., and other Canadian firms, said officials from the Duluth Port Authority and the international Chamber of Marine Commerce. They not only carried ore shipments to steel mills inside Canada, but also transferred pellets to larger international ships at Canadian Ports on the seaway. Those ships ultimately transported the ore from Minnesota's Iron Range to China, Japan and other overseas destinations.

"We've seen strong volumes in many of our cargoes, but particularly iron-ore pellet exports from Minnesota that our ships are carrying to the Port of Quebec for transshipment overseas," said Gregg Ruhl, Algoma's chief operating officer, in a statement. "We expect those exports to continue in the fourth quarter. Our ships are fully booked for the rest of the 2017 shipping season."

Through September, overall iron-ore shipments out of Duluth jumped 36 percent to 13.7 million tons over the same period in 2016, according to the Duluth Seaway Port Authority. Ore shipments out of Minnesota's Two Harbors and Silver Bay ports, as well as from Superior, Wis., also saw significant increases through September.

Increased iron-pellet shipments are "dominating waterborne commerce in the Port of Duluth-Superior this shipping season," said Vanta Coda, executive director of the Duluth Seaway Port Authority.

This year's shipments have outpaced the port's five-year average by more than 20 percent, with overseas shipments delivering the "lion's share of the rally," Coda said.

At the same time, the Canadian business has increased, U.S. steel mills along the Great Lakes also ratcheted orders for iron ore, the key ingredient to steelmaking, said Port Authority spokeswoman Adele Yorde. "This year, it's just been bucket loads of iron ore" in demand, she said.

The surge in Minnesota ore cargo helped boost total seaway shipments by 10 percent from a year ago.

Including ore, salt, construction equipment, grains and other bulk dry goods, total cargo shipments traveling the Great Lakes-St. Lawrence Seaway rose 2.5 million tons to 28.7 million tons, Marine Commerce officials said. That increase reflects tonnage transported from the start of the shipping season on March 20 through Oct. 31, said Bruce Burrows, president of the Chamber of Marine Commerce.

"This year, cargo volumes have improved in everything from mined products like iron ore and salt to construction materials and general cargo," Burrows said. "The next couple of months are traditionally the busiest of the year with customers stockpiling raw materials for winter production. We're optimistic 2017 will end on a positive note."

That confidence bodes well for Minnesota's Iron Range, which continues to recover from a brutal downturn and international pricing slump that forced several taconite plants here to halt production and lay off 2,000 workers between 2014 and 2016.

Today, however, several "taconite facilities on the Iron Range are back in production and there's been a significant increase in demand in both domestic and overseas markets for iron ore this season," Yorde said.

Once-idled mines and ore-pelletizing plants at United Taconite in Forbes/Eveleth; Northshore Mining in Babbitt and Silver Bay; Minntac in Mountain Iron; and Keetac in Keewatin have come back online in the last 20 or so months. Even so, other firms are still struggling.

The former Magnetation, which processed spent ore tailings into usable ore, has yet to restart production in Grand Rapids, or its former locations in Bovey, Coleraine or Keewatin. Magnetation filed for bankruptcy in May 2015. Earlier this year, it was sold to billionaire Tom Clarke's ERP Iron Ore LLC.

In the spring, Clarke told the Star Tribune that he hoped to restart production in Grand Rapids soon. But progress there has largely stalled, local trades groups said.

Separately, state officials are hoping that another company led by Clarke can jump-start Essar Steel Minnesota, which filed for bankruptcy in July 2016 after halting construction of a $1.9 billion iron ore processing facility in Nashwauk.

Chippewa Capital Partners is in the final stages of buying the old Essar property out of bankruptcy court. If the sale is completed and construction resumes, the Nashwauk plant isn't expected to begin producing iron ore for another two years, Clarke said.