MINNEAPOLIS (AP) — Construction delays dashed hopes for a July opening of the highly anticipated campground at the newest gem in Minnesota's state park system, but officials are still holding out hope that it might be ready in time for the fall color season.

There's still work to be done at Lake Vermilion-Soudan Underground Mine State Park , said Scott Kelling, northeast regional manager for parks and trails at the Department of Natural Resources.

"We're hopeful it will happen this year," Kelling said in an interview Thursday. "We will not be doing a grand opening. It will probably be a softer approach once we decide we can open. We've got our sights set on a September opening with a date to be confirmed."

The state agreed to buy the 3,000-acre site and its picture-postcard views from U.S. Steel in 2008. The $18 million sale closed in 2010, saving the land from being developed into expensive vacation homes. It was already adjacent to Soudan Underground Mine State Park, which dates from 1963, giving the combined operation 4,000 acres and 10 miles of shoreline on a lake dotted with nearly 400 islands that's just a portage away from the Boundary Waters Canoe Area Wilderness.

The DNR broke ground on the campground in 2015. It's designed to accommodate more than 250 nightly guests in tents and recreational vehicles. Demand for the spaces is expected to be high. Visits across the entire state park system surged to a record 10 million last year. The DNR expects the new park to draw around 250,000 visitors annually once it's fully developed.

"We're confident we'll be able to run a full camping season in 2018," Kelling said.

A major reason for the delays is that the park is piloting a new signage system, and Kelling said the fabrication and installation has taken longer than expected. Information kiosks remain under construction because some materials were substandard and had to be sent back. Rain slowed construction, too. A key entrance sign isn't expected to arrive until the end of the month. Building roads, septic systems and water systems on the rocky terrain has been complicated, too.

"We know a lot of people are anxious for it to open and we are too. But we want to make sure we make a good first impression and that our customers have an unforgettable experience when they meet the park — for all the right reasons. And once it's open it'll be open for a long time to come," he said.