On September 3, 1609, English explorer Henry Hudson and his crew of Dutch and British sailors turned their 85-foot sailboat, the Half Moon, up a great waterway. They thought it might be a new route to the Far East.

The Half Moon had been searching for that route, the Northwest Passage, from Scandinavia to present-day Maine and South Carolina.

They never located a passage slicing across the North American continent to the Pacific Ocean. The expedition did discover a river, rippling with fish, that cut through a wooded land bursting with natural resources. The river would later be named the Hudson River in the explorer’s honor.

William T. “Chip” Reynolds is director of the New Netherland Museum and captain of a replica of the Half Moon. This replica has recreated Hudson’s voyage up the river to Albany, N.Y., every year since 1999. Reynolds says that Hudson must have immediately known the importance of his discovery.

“Here Hudson comes over, and seeing this North America continent through the eyes of a European has to be stunning,” Reynolds says. “You have these expansive natural harbors. You have these shipbuilding timbers that are available right at the river’s edge. You have plentiful fish. You have fur-bearing mammals. This is a veritable Garden of Eden to them.”

Every fall, Reynolds sets sail up the Hudson River with a crew of a dozen 12-year-old students in a replica of the Half Moon and traces Hudson’s journey up the waterway. Though the Half Moon replica is outfitted with modern technology, including a global positioning system (GPS), Reynolds says the students handle the sails like Hudson’s crew and employ the same navigation tools, including a compass to find their way upriver.

In 2009, New York celebrated the 400th anniversary of Hudson’s discovery, which showered more attention on Reynolds and the Half Moon’s annual voyage upriver. The sailboat was accompanied by a handful of Dutch frigates and NATO naval vessels as it left New York Harbor on its way up the Hudson.

Changes to the Waterway

Having followed Hudson’s route up the river every fall for the last decade, Reynolds is able to easily reel off a handful of ways the waterway has changed, and stayed the same, since the explorer’s initial explorations of the region.

Reynolds says that even within sight of New York City’s skyline, where skyscrapers rise like jagged crystals, one can take in the magnificent natural scenery that the explorer encountered.

“In virtually an entire section of the Hudson River, we are able to sail and see exactly the same circumstances that Hudson saw, even when we are right in the vicinity of New York City,” he says. “As you are sailing along the Palisades (cliffs along the lower river in New York and New Jersey), you can look to one side and see one of the densest urban areas in the world and look in the other direction and you’ll see a view that is exactly the view that Henry Hudson saw 400 years ago.”

Reynolds also notes that the river is essentially unchanged in the Hudson Highlands, a mountainous region between Newburgh Bay and Haverstraw Bay. Only a few buildings and the Bear Mountain Bridge, which spans the Hudson near Peekskill, N.Y., dot the shore.

“We have charts from the 1630s that provide depths and sailing directions that we can follow to this day,” Reynolds says. “We can take the soundings and the reaches that are described in the log from 1609, as reported and recorded by Robert Juet (one of Hudson’s officers), and sail exactly as he described and precede from Upper Haverstraw Bay right through the Highlands and up into Newburgh Bay with no change.”

Of course, there’s a large section of the Lower Hudson River Valley that has been significantly altered due to its proximity to New York City, the most densely populated city in the United States. Reynolds admits that the Upper Hudson River Valley, a portion of the waterway north of the town of Catskill, N.Y., is also not the same as Hudson initially saw it.

“From the late 19th century to now, that run of shoreline has been heavily stabilized with the dredging of a navigational channel, with stabilization of the shoreline, with the damming of the Upper Hudson River that controls seasonal flooding to reduce it,” he says.

One dramatic alteration of the Hudson River has been caused by the dumping of pollutants in the water since the arrival of the Europeans in the area. The polluting of the Hudson River has contributed to the declining fish population there. From reading Juet’s log from Hudson’s journey, one can observe changes in the local fish and animal populations since the river was first explored. There are many entries that describe the river’s vast reserves of fish and oysters, which have diminished since the area was settled by Europeans and eventually became a part of the United States.

As the Half Moon inched into the mouth of the river 400 years ago, Juet remarked of seeing many salmon, mullets and rays. The next day, Juet wrote: “our boat went on land with our net to fish, and caught 10 great mullets, of a foot and a half long a piece and a ray as great as four men could haul into the ship.”

Recovering Environment

Unfortunately, on his annual trips up the Hudson River, Reynolds has been unable to encounter the natural bounty that Hudson witnessed, even though he says the river has been rebounding since the passage of 1972’s Clean Water Act, which sought to reduce the direct discharge of pollutants into the nation’s waterways.

“Fish populations have dramatically declined from Hudson’s time, but they are resurging,” Reynolds says. “We’ve lost several species that have been really hard hit: sturgeon, shad, stripers, herring.”

Meanwhile, another entry in Juet’s journal describes Hudson’s crew trading beads, knives and hatchets for the native inhabitants’ supplies of beaver and otter skins. Though one species is not as prevalent in the Hudson River Valley as it was in Hudson’s day, Reynolds notes that certain animals have returned to the area in impressive numbers over the last decade and a half.

“We have not observed any otter in the navigable portion of the Hudson River, but we’ve observed beaver,” he says. “We’ve observed muskrat. We’ve seen deer. We’ve seen fox. We’ve seen eagles. We’ve seen ospreys. Fifteen years ago, it was quite a special thing to see an eagle in the Hudson River Valley. Now, it’s unusual if we don’t see an eagle when we are traveling anywhere in the Hudson Valley even for a day.”