As American bald eagles congregate in peak numbers this month around Lake City, Wabasha and other southeastern Minnesota river towns, there's more happening than meets the eye.

In spacious nests aloft, eaglets are emerging from clutches of eggs that have been incubating for a month.

In the bluffs and backwoods of the Upper Mississippi River Valley, a few traces remain of an elusive assortment of migratory, wintering golden eagles.

And in offices at the expansion-minded National Eagle Center, staff members are buzzing about bountiful bald eagle counts, increasing visitor traffic, a popular golden eagle project and a 20,000-piece collection of museum-quality eagle depictions that recently moved to Wabasha from San Francisco.

March is "Soar with the Eagles'' month at the eagle center, and things are looking up. It's the region's busiest time for bald eagle viewing, and visitors receive special programming every March weekend. The finale on March 25-26 is a showcase of exotic birds from around the world transported to Wabasha by the Cincinnati Zoo.

"We need more space,'' said Rolf Thompson, executive director of the nonprofit eagle center.

Last weekend, nearly 1,400 people attended the opening of "Soar with the Eagles.'' Then, on Monday, the center welcomed to its staff a full-time development director, Andrea Chapman. She'll have a $5 million state bonding request to cultivate along with bringing in additional funding to renovate four Main Street buildings already acquired by the eagle center. Thompson said the planned, $15 million expansion envisions a theatre-style auditorium to support the center's everyday live eagle demonstrations and educational efforts. In addition, the city of Wabasha is trying to attract a hotel developer.

Thompson said more space is needed in part to accommodate the extraordinary collection of historical eagle representations and eagle-themed fine art owned by Preston Cook, who moved to Wabasha in the past year from San Francisco. For the time being, Cook is keeping the collection in a local warehouse.

"He wants to move from hoarding it to sharing it,'' Thompson said. "It's an incredible opportunity.''

The eagle center foresees a rollout of themed displays, such as eagle symbolism in the American military. The collection's historical pieces include a document signed by Abraham Lincoln with an eagle design.

If the planned expansion materializes, Thompson foresees 50 percent attendance growth and more captive eagles for viewing. The current stable is six live eagles. Last year's attendance mark of 83,000 visitors was up 5 percent from 2015. Attendance growth from 2014 to 2015 was 9 percent.

Especially in March, the obvious nexus for the eagle center's success is public viewing of wild eagles up and down the Mississippi. Last weekend, a Twin Cities couple counted 180 bald eagles en route to Wabasha, said Scott Mehus, education director at the center. The region hosts a vibrant population of eagles year-round, but the density of birds blossoms in March from the influx of migratory bald eagles returning to northern Minnesota and Canada.

"The counts are good right now,'' Mehus said. "Just phenomenal viewing the last couple of weeks.''

Until recent ice-outs, the majestic birds could be seen in groups of 20 or more on ice shelves that cupped open water on Lake Pepin and secondary river channels. When the river's backwaters thaw, there could be similar sightings.

Otherwise, Mehus said, the best viewing this month will be on sunny days when winds are out of the south. That's when bald eagles ride thermal currents high into the sky, allowing themselves to get pushed north by the wind.

Home sweet home

Only Alaska has a greater nesting population of bald eagles than Minnesota. According to a ranking by the U.S. Fish and Wildlife Service, Minnesota surveyed 1,312 nesting pairs in 2005. One of those, located in the Twin Cities, is spied upon by a wireless DNR camera. The two eagles who live under the lens made an internet splash last week while one of their chicks hatched. The live video stream drew as many as 1,500 simultaneous viewers via desktop computers and mobile devices.

"There's definitely more traffic this week,'' the DNR's Jed Becher said Thursday.

He said this year's EagleCam, operational since Jan. 27, has drawn viewers from every state and 100 different countries. More than 100,000 unique devices have watched the live stream more than a half-million times.

Banana belt

Viewing of golden eagles in Minnesota is catching on but remains limited by a much smaller grouping, a short season and more remote habitat. The brown and black birds are similar in size to bald eagles, tinged with white highlights. They're often mistaken for immature bald eagles that haven't yet developed signature white plumage.

In 2005, 24 trained observers organized by the National Eagle Center counted 21 golden eagles in surrounding bluff country. The birds arrive in mid- to late October from extreme northern Canada, staying until late February or early March.

"We're the banana belt for golden eagles,'' DNR naturalist Carrol Henderson said.

Mehus said the center's annual survey of migratory golden eagles — always conducted on the third Saturday of January — has grown more popular each year. This year's count was hampered by heavy fog, but 200 volunteers in 2016 counted 147 golden eagles in the area, he said.

The surveys are part of a project that seeks to better understand and protect golden eagle habitat in Minnesota, Mehus said, adding, "We get to enjoy them here for a couple of months.''

Golden eagles also are known to winter in central Minnesota, including in the secluded woods of Camp Ripley. There, the DNR banded a female golden eagle in March 2015. Known as "Ripley,'' she has returned for the past two winters and was still on Camp property last weekend.

"She comes down in late December and moves north in early March,'' said Brian Dirks of the DNR.

The transmitter on Ripley's leg indicates that she "summers'' inside the Arctic Circle on the cliff-sided banks of the Coppermine River near Kugluktuk, a tiny village on the seashore of Canada's northernmost territory.

Said Mehus: "This is the good time of the year for migration and it's definitely on right now.''