The river at night belongs to me. Me, and my sturgeon kin, my heron pals, the moon, the frantic bugs that prick my face and arms. Those bugs force me to keep my mouth sealed: they dare me to swallow them.

The Hudson River is an arm of the Atlantic Ocean, pulling in and out with the tides the 154 miles from Manhattan to Albany. I’ve paddled the length of the river, from Schodack Island to Manhattan. Twice during a long, thrilling day, I’ve circumnavigated Manhattan. I know where the river spreads wide, to three miles, at Haverstraw Bay above the Tappan Zee Bridge, and where it drops deep at World’s End near West Point. I know what stretches are ugly with industry and where everything fades to green, like an untouched wilderness. But the section I know best is off of my home in the village of Tivoli. I know the houses on shore, where I’ll see a bald eagle or snapping turtle, and where my paddles will tangle in water chestnut. I have explored this reach at dawn and dusk, at high noon when I have to squint for the glare of the sun as it reflects off the smooth water, and through windy afternoons when whitecaps froth the surface of the water. I call this section, this reach of river, mine.

A reach is a stretch of river, measured by how far a navigator can see into the distance before a river takes a bend. There are long reaches on the Hudson, like the 13-mile Long Reach off the city of Poughkeepsie. The Tivoli Reach is but a thousand feet long. Rogers Reach, which exists in my imagination, stretches from the Saugerties Lighthouse to the South Tivoli Bay, a distance of about two miles.

I have gone to my reach for adventure, for solace, for inspiration. I have gone to know myself and to intimately know this big river. But in order to know my reach in all of its rich complexity, I needed to navigate the currents and eddies in the dark. Night is the realm of secrets, of animal instincts. I wanted the thrill of exploring by feel and taste and sound. And so at the end of a hot summer day, the sort that leaves me restless, even cranky, I slide my kayak into the water at 11 at night. The moon, obscured by clouds, is near full; the lights from the Saugerties Lighthouse blink across the way. I step into the summer-warmed water and slip into my boat.

I leave the yellow lights of the village. I’m surrounded by ink from below and a cool black blanket from above. Tucking in near shore, I paddle in the shadows of the trees. My disorientation is complete; I stroke toward the middle of the river. I lose any sense of the depth of the water. Outside of the shipping channel, the river in my reach is relatively shallow, 10 feet deep or less in many places, but there in the night it feels like it drops hundreds of feet. I skim the surface as if on a high balance beam. My heart races. This fear has always been a part of my outdoor adventures. It’s the fear that keeps me alert, reminds me of the dangers, insists I keep a tight hold on this life.

As I near Magdalen Island, which lies huddled in the dark, the moon appears from behind the clouds to glow, a lopsided, orange-red ball. I hear voices, a low mumble carrying across the water. Perhaps someone is camping on the island? And then I spy a boat anchored on the far shore. I smell the faint perfume of a two-stroke engine, covering up the familiar mixture of creosote-laced water.

At the end of Magdalen a great blue heron drops out of a tree to croak its discontent; I’ve disturbed its roost for the night. I slush through the shallow water on the east side of the island. I hear the echo of a great horned owl across the North Tivoli Bay.

When I emerge from the cozy swatch of river wedged between the shore and the island, the shadows lift and I can see the shape of the shoreline and the shape of something large and unexpected on the water. A tug rumbles by, towing a long, invisible barge. A parade of fiery lights whooshes past. The wake of the barge rocks my slim kayak, a dizzying up and down.

I make my way back north. Smack. Something strikes the hull of my boat. I cry out in alarm before I realize: it’s a fish. I imagine a long, primitive sturgeon making its way through the dark, shallow waters.

I stroke against the outgoing tide. An Amtrak train interrupts the silence, its horn long and insistent. The rumble seems to shake the foundation of the river until it calms once again.

I swing out wide to avoid the remains of a 19th century dock. The lights of Tivoli beckon. I glide toward the shore between two boulders and bring my kayak to rest on the gravel shoreline.

The river has worked its magic: the heat of the day has been replaced by the lights on shore, the lopsided orange moon, a rush of excitement at the slap of a fish.