After a long hike, author Laura Wainwright made a cranberry-walnut pie. — Olga Berman

The only place I know to see cranberries growing is in the tiny bog by the main holding pond at Cranberry Acres. A sweet trail circles this pond, and I often walk it, always pausing at the bog to see if the fruit has changed from white to a deep rich red.

Today in honor of Cranberry Day, always the second Tuesday in October, I want to go see the ripe berries. For the first time this season I take a jacket down from a peg in our mudroom and reluctantly put it on. It’s cool this afternoon. Piling our two old dogs into the car, I drive the few minutes down the Lambert’s Cove Road to Blackwater Pond Reservation to meet up with a friend.

We pick up the trail to Cranberry Acres alongside the Hoft Farm barn. A former road, the trail meanders through the oak and pinewoods, before ending abruptly at the main pond at Cranberry Acres. Everything is shiny in the low afternoon light. Fallen leaves hold little sparkling puddles of last night’s rain. The dogs race ahead barking, delighted by the cooler weather.

The October sun glistens off the backs of turtles and the green heads of mallards dotting the pond. Following a rim of emerald green moss to the right, soon we are walking on a pair of narrow wooden boards edged on both sides by the ripe red fruit. The ground is moist and the low plants gleam. A sign posted by the Vineyard Open Land Foundation, the steward of this restoration project, reminds us to look, not pick. I want to roll a smooth skinned fruit between my fingers and rub a sprig of the tiny, shiny green leaves across my cheek. Just looking is hard, but I keep my hands in my pockets.

A peculiar abundance of animal life teems in this small pond. The ducks make a racket, and there are more turtles than we can count. Frogs create a steady stream of splashes by leaping into the water as we approach. The dappled light of the woods is cool, so when we return to the open fields of the Nature Conservancy’s Hoft Farm we can’t resist the pull of full sun and decide to meander through the still green fields.

At one edge, the trail skims the rim of one of the Blackwater Ponds, which I’ve just read were holding ponds for cranberry production. I’m describing this to [my friend] Margi when we both look down. We are standing in a dense patch of cranberries. There are no signs here.

In unison we drop to the ground, kneel among the vines and begin to pick. The vine’s tiny leaves are soft to the touch. Spreading them gently apart, we find fruit in abundance. Laughing with delight, I gather with both hands, grateful for the ample pockets of my warm coat. In no time they are full of luscious ripe red fruit. I keep dipping my hands into my pockets again and again to feel the smooth surface of the shiny berries slipping between my fingers. They are dry and light.

Back at my house we pool our fruits into a metal colander. There are exactly four cups, two for each of us. This is just what I need to make my favorite cranberry dessert — a cranberry walnut pie. While the oven warms I gather the ingredients and the recipe. The recipe is handwritten on the grey registration card of a bed-and-breakfast in Duluth, Iowa, where I first tasted the pie in 1998. That day it was the first course of a five-course breakfast. It surprised me to have what I thought of as a local delicacy in Iowa. My hosts laughed at their provincial guest and told me the state of Wisconsin, just across the Mississippi River from Duluth, is the leading producer of cranberries in the United States. Massachusetts is second.

Each time I make this pie I’m amazed something so delicious can be so simple, but this time I feel a special pride because I have gathered these berries with the pleasure of my own hands. The kitchen fills with the fragrance of cooked cranberries. For a moment, I consider taking the pie to the Wampanoag potluck.

The day of harvesting cranberries from the communal bogs is for tribe members only, but the evening dancing, drumming and eating is open to everyone on the Island. It’s tempting but the fire is lit, and my family will be home soon. I’m glad Cranberry Day happens every year, so tonight we can savor this unexpected autumn treat right here at home.

Recipe for Cranberry Walnut Pie

9-inch unbaked pie crust
2 cups whole cranberries
1 cup whole walnut halves
1/4 cup brown sugar
1 egg
1/2 cup sugar
1/3 cup butter, melted and cooled
1/2 cup flour

Set the oven to 325 degrees. Place cranberries and walnuts in pie shell. Sprinkle with brown sugar. Combine egg, sugar, and flour. Beat well. Spread on top of fruit and nut mixture. Bake 45-50 minutes.

Excerpted from “Home Bird: Four Seasons on Martha’s Vineyard,” by Laura Wainwright, published in 2012 by Vineyard Stories, available at Bunch of Grapes, Edgartown Books and the Allen Farm. Photo of pie by Olga Berman.