We came by boat to watch the cheetahs of the sky.

The fastest of the avians, they dive-bomb into a colony of avocets, who scurry through the shallows on chopstick-slender legs. The avocets stay low, hoping the crouch will protect them. But the speedy peregrine falcons sweep lower, intimidating the graceful shorebirds for a moment before moving on to nearby bufflehead ducks.

Rare birds abound on Hart-Miller Island off the mouth of Back River in the Chesapeake Bay — a red-breasted merganser here, an orange-crowned warbler there. Less than a mile from the mainland, the 1,140-acre island is an unnatural natural place. Engineers combined two remnant islands (Hart and Miller) with about 100 million cubic yards of shipping channel muck to form a wildlife paradise about a dozen miles from downtown Baltimore.

That’s why the Maryland Environmental Service runs free trips for birders to the island, carrying groups like ours of mostly dedicated birders with high-priced scopes and long-lensed cameras five miles down Back River and out to the island’s dock for a tour. Baltimore County officials want to make the island, reachable only by boat, accessible to more people. (The next tour is Dec. 18.)

An engineering project conceived to hold dredge material from Baltimore’s harbor and keep the port’s shipping economy humming quickly evolved to fulfill other goals. Hart-Miller’s large landmass slows wave action and stems erosion. Its meticulously restored marshlands beckon waterfowl and shorebirds, and its native plants and trees have encouraged nesting populations of rare and common songbirds and owls.

All of that begs to be seen, especially by state taxpayers who financed — to the tune of more than $108 million — the shift from two uninhabited remnant islands to 1,100 acres of connected and managed habitat. And yet a common worry is that, if government officials swing open the doors to Hart-Miller, people might love it to death.

“People should see this,” said Tim Carney, a senior environmental specialist with the Maryland Environmental Service, as he looked for loons next to a shallow pond full of ruddy ducks and pintails. “There’s really nowhere around here where you can see this many ducks in a single spot.”

Hart-Miller Island is a joint project of the Maryland Port Administration, which managed the dredging until it stopped in 2009, and the Maryland Department of Natural Resources, which opened about 300 acres of the island as a beachfront state park eight years ago. The environmental service, a state nonprofit, manages the site.

Baltimore County officials would like to make it easier to get there for residents, many of whom picked up hiking, biking and birding while cooped up during the pandemic. The beach, which is a state park, is open from April to October, but visitors must use their own boats to get there.

The remainder of the year, the only way to see the island is on a monthly tour (twice monthly in the summer) with MES, which runs bird tours through online lottery sign-ups; Carney and his team give priority to first-time visitors. MES arranges tours for birding clubs and groups, who rave about the diversity of species. Carney said demand has quadrupled since he began the tours and is even higher when a rare bird such as a snowy owl shows up.

A few months ago, county officials hoped that greater accessibility had finally found its way to the island.

Tradepoint Atlantic, the massive logistics development that’s replaced the old steel mill at Sparrows Point, wanted to place 4 million cubic yards of river bottom muck at the island to dredge channels for a new container terminal. In exchange, the company offered the community $40 million in benefit funds, some of which could have been spent to subsidize transit to the island. After some nearby residents resisted the idea of placing more material on the island, Tradepoint scrapped the project.

The outcome did not surprise longtime residents, who were so opposed to depositing dredge materials from the Patapsco River and the main Chesapeake channels in the 1990s that they fought it all the way to the U.S. Supreme Court. The dredging that created today’s birding paradise began only because the high court refused to hear the case.

County Councilmember Todd Crandell, who had represented the area for a decade, called the opposition and Tradepoint’s decision disappointing.

“On the other hand,” he said, “it did give additional attention to an island that was planned 35 years ago to become a state park but really hasn’t been invested in since then.”

Crandell said, if the state finishes its habitat restoration plans for the part of the island that remains closed, he will advocate for Baltimore County to create access points at parks along the shoreline to make it easier to get to Hart-Miller.

County officials referred questions on plans for the island to Karen Wynn, a member of the Community Benefit Agreement Steering Committee for the Tradepoint deal. Wynn, who is also active in the Friends of Hart-Miller Island group, said the loss of the money was due to misinformation and fear of an environmental disaster that was unlikely to occur, given nearly three decades of dredging with little contamination.

“We definitely would like the island to be more accessible,” said Wynn, adding that the committee was looking into a ferry boat and a new pier where citizens could tie up.

The current pier belongs to MES, so other visitors must find a shoal and then moor their boats. Wynn said both of her organizations are looking for grants to improve activities on the island, including adding more bicycles for use in the summer at the state park.

Department of Natural Resources spokesperson Gregg Bortz said the state has been in discussion with the Hart-Miiller friends group about the best ways to restore habitat on the island’s northern end. But, Bortz said, there are “no specific plans for added access from shore at this point.”

Birders understand the access conundrum.

“You definitely want people to be able to get out here and appreciate it, but if you bring too many people that will affect the wildlife,” said Ian Moody, a Hampden data entry specialist who joined our birding group with his mother, Susan. “It’s like the way birders, if they find an owl, they will not share the exact location. They don’t want someone to knock on the tree just to get that photo.”

Hart-Miller’s success has spawned other projects. Poplar Island, on the Eastern Shore, was once a thriving community that all but eroded into the bay. A dredging project that began in 2001 is restoring 1,715 acres of marsh and wetland habitat there and bringing with it dozens of bird and fish species. A plan to place dredge material at Barren and James islands in the mid-Chesapeake is even more ambitious, seeking to restore 2,072 acres of habitat and protect nearby towns from wave action that leads to erosion and flooding.

Eight years ago, on my last visit, parts of Hart-Miller had not yet filled in. Parts resembled a moonscape. Not so now. Native grasses sway in the breeze as Carney uses a recording to call a Virginia rail; the rail answers as eagerly as a first grader raising her hand high in the front row. Then tundra swans, in formation like Air Force cadets, glide through the cloud-swirled sky. There are red-wing blackbirds in the tall sweet gum, a field sparrow in low brush.

Every minute, it seems, expert birder Keith Costley of Randallstown calls out a new bird to add to the list (there are more than 300 on it). Each provides clues about our environment. Avocets should be gone already, but the drought has tricked them into believing their pond is shorebird habitat. The glossy ibis belongs in Florida; a warming Earth has it confused.

The birders’ scopes and patience show me many birds I have never seen before, but some that excite them the most I can’t spot. Looking for a red-breasted merganser in a pond of dabbling ducks feels like failure.

Susan Moody turns and smiles.

“That’s the challenge,” she says. “That’s why we keep looking.”