♪ ♪ - As seen from space, Wisconsin's thumb of land, Door County, juts out between Lake Michigan and Green Bay, part of a rock formation called the Niagara Escarpment.

- The Niagara Escarpment is about a 1,000-mile long ridge of rock that runs through Door County, all the way up into the Upper Peninsula of Michigan, into Ontario, Canada, and ends around Niagara Falls.

It's actually the rock that Niagara Falls flows over.

And if you look at the rocks here, you'll see there are these really beautiful, tall cliffs on the western side of the peninsula.

The cliff is called an escarpment because it's a steep vertical cliff.

- Glaciers formed the peninsula of Door County during the last ice age.

- When the ice hit that ridge of rock, it actually split it into two different lobes that then actually carved out Lake Michigan and Green Bay because of the Niagara Escarpment.

- As the glaciers retreated, Paleo-Indians arrived in the area now known as Sturgeon Bay, and set up camp sites.

Here, archeologists found spear points and stone tools, used over 10,000 years ago to hunt and process large game.

Archaeologists also found evidence throughout the county of many groups and tribes, drawn for thousands of years, to the rich hunting and fishing grounds of Door County.

Many of the early European settlers came to the remote islands north of the peninsula, taking advantage of waters teeming with fish.

- By 1860, there was close to 200 people on Rock Island, 200 on St. Martin's.

And, of course, the boats were double-enders, wooden boats, Mackinaw boats.

They were light boats, a lot of them were made of cedar, so with a man on each side, you could pull them right up on any beach, any gravel beach.

And you didn't need a dock, and that was important, because you wanted to be close to your fishery.

After all, you either rowed or you sailed, not easy.

And especially if there wasn't much wind, then you rowed, period.

Of course, with the Mackinaw boats, everything was done by hand, you pulled the nets by hand.

Deadly work, you know.

But that's the history of the fishery.

There was an awful lot of hard work in it.

- Asa Thorp, after a season of making barrels for the fishermen on Rock Island, boarded a steamer bound for Green Bay.

- And the captain was sort of telling him his woes about how difficult it is to run this side of the bay.

There were no villages, there were no docks.

So they would have to anchor, send the men into the shore and collect driftwood to burn for the steamers.

And the captain said, "If a guy were smart, this is where he'd put a dock."

- Thorp took the advice, and built a dock, and eventually a sawmill, at Fish Creek, to take part in the harvest of the heavy forest that covered Door County.

- Very, very deep forest; very mature forest.

North, was largely pine; very good pine.

And then they had hemlocks along on the sandy shores.

And in the swamps, they had the cedar.

And then, they also had maple and birch and tamarack.

A person would buy maybe 2,000 acres and they would get a sawmill into the area.

And the peninsula of Door County doesn't have any navigable streams, so all the logs had to be transported to the shore.

And around the area of Door County, at one time, there were 60 docks and there were about 66 sawmills.

- Using the variety of local woods, local shipbuilders built schooners to carry the lumber to market.

Many of the boats traveled around the tip of the peninsula, through Death's Door, the treacherous passage that gave the county its name.

- When you were going to Chicago, if you could go through Death's Door, instead of coming up to the Rock Island passage, you might save a day of sailing.

And, of course, a lot of these skippers had great confidence in their own ability.

And it didn't always work out so well, because that's a very treacherous water.

When you get strong winds, quite often the current is into the wind very strong, and you can't see it.

When you get into the middle of that and you've got all your sail up and you're not going ahead, you're in big trouble.

Big ships, 150-footers...

The Resumption went aground on Plum Island.

Beautiful big ships, you know.

There were three of them went aground on Pilot Island within a couple weeks in one fall.

So there are dozens of shipwrecks on that Death's Door passage.

- As the loggers moved on, families began to settle onto the land, and build farms.

- And it was a tough go.

The hardships are beyond our imagination, really.

There were places they could get enough topsoil to plant crops, and they did-- there was quite a bit of farming up here.

But it was a tough kind of farming.

- First, they had to clear the land, and then pull the stumps, and a huge, labor-intensive-- Terrible, you know.

And then when they put the plow in the ground, all they got was rocks.

(laughing) - So if you drive through the county, in almost any village, you will see beautiful, constructed stone fences, and thrown-together stone fences.

- Those are symbols of hard-gained cropland.

- As farms developed, villages grew up around the loading docks.

The settlers built schools, and churches, and endured long, and often brutal, winters.

- A lot of disease.

A lot of them died of whooping cough, tuberculosis, plague.

But we owe them a tremendous debt of gratitude, and we cannot appreciate what they went through to settle this area.