Nature Trail

Mianus River Park Nature Trail

The trail is marked with green blazes painted on trees along the way. There are thirteen points of interest, marked by lettered green posts (A-M), covering a variety of features found throughout the park. They can be used as a starting point for further study or simply as a brief description of what can be noted during a walk in the woods. The route is about two and a half miles in length and takes about two hours to complete at a leisurely pace. This is a wonderful activity for families to do as they explore the park.

Map and Guide

(A) Mianus River Park

What is the history of the park?

The park had its beginnings in the late 1960s when Stamford bought 77 acres in the Westover neighborhood. In 1972, the park quadrupled in size when Greenwich purchased 110 acres and Stamford another 110 from the Goodbody Estate. The final 94 acres were added in 2000 when the state of Connecticut purchased the former Libby Holman estate. Over the years, various individuals and families owned different parcels of the land often as a second or third home. Several well known people of the day including, Dr. Robert Morris, Libby Holman and the Havemeyer and Goodbody families owned parts of the property. President Grover Cleveland fished the river with Dr. Morris while Reverend Martin Luther King and Coretta Scott King visited Libby Holman at Treetops.

To the left of the gate, on a flat rock is a plaque honoring Mr. Fish who was one of those responsible for Stamford’s acquisition.

(B) Mianus River & Urban Oasis

What is the importance of the Mianus River to the local environment?

A watershed is like a big bathtub, water that falls anywhere within the bathtub will move downhill to its drain. The 42 square mile Mianus River watershed area includes Bedford, North Castle and Pound Ridge in New York, as well as Greenwich and Stamford in Connecticut. The river, its tributaries, the wetlands, woods and fields provide the habitat to support diverse and abundant wildlife, as well as ideal settings for recreational activities that respect the delicate balance of nature.

The Mianus River watershed provides the public drinking water source for over 100,000 people in Greenwich, Stamford, Port Chester, Rye and Rye Brook so water quality is very important.

What is an “Urban Oasis"?

Tens of millions of song birds follow the Atlantic Migratory Flyway twice a year on their amazing long distance seasonal migrations. The Friends of Mianus River Park, together with Greenwich Audubon, have created this “urban oasis” of bird-friendly native plants for birds to rest and refuel on their journeys. You can learn more about birds and urban oases at

(C) Hardened Access

Why are there rocks built into the river bank here?

A Hardened Access allows people and animals to enter and leave the river without dragging in soil, which damages the fragile creatures and plants living in the river. The educational panel to the right provides more details on how erosion impacts the river’s health.

Various organizations including state and local governments, environmental groups and Aquarion Water Company published a Mianus River watershed plan in 2012. It provides guidance for individuals, organizations and municipalities on preventing pollution and increasing awareness of the valuable resources within the watershed area. Education, understanding, cooperation and enforcement of laws helps to ensure that pollutant levels in the river remain low and living conditions high.

(D) The Field

What is special about this part of the park?

As recently as the middle of last century, this was a cleared field. Since that time it has been allowed to revert to its natural state. When a forest is destroyed, whether by human foresting or natural causes, it begins to repair itself through plant succession. First scrub, next small plants and finally trees develop into a forest. It can take from 600 to 1,000 years for a forest to rebuild without human intervention. Because this area is still part field and part forest, it attracts many different types of birds, animals and insects.

(E) Stone Walls

Why are there stone walls here and in other parts of the park?

A century ago nearly 90% of New England was cleared for agriculture. It is amazing how little of this past remains. Stone walls fences marked the farmer’s field boundaries. It was once said that a farmer’s stone walls were more important than his cattle, crops and the land they enclosed. In 1871, a survey recorded that one-third of the fences in Connecticut were made of stone, some 20,500 miles of them and enough to circle three quarters of planet earth.

For further information on stone walls visit: The Stone Wall Initiative

(F) The Highest Point (270 feet)

How did this big rock formation get here?

The rock was formed about 500 million years ago during the Ordovician period. It lay deep underground until the most recent ice age some 20,000 years ago. The topsoil was scraped away by the receding glaciers exposing the rock to view. You can also see many glacial “erratics” which are large rocks left improbable places by receding glaciers.

How are trees able to grow out of rocks?

The trees are not actually growing out of the rock, but on top of it, in cracks, or around it. First lichens and moss grow on the rock. These simple life forms are able to draw nutrients from the rock itself. After some years these mosses die and make a mat of humus or decaying organic material. A seed falls into this rich mat, germinates, grows, then dies, leaving behind additional detritus to continue the cycle. Soon larger plants and trees take hold and grow to the size you see here as well as in other areas of the park.

(G) The Wetlands

What do you think lives here?

The wetlands are probably the most important part of the local ecology. These swamps are a rich source of food for animals and birds and offer homes to aquatic creatures, such as salamanders, turtles and snakes. The wetlands also provide shelter and fresh water for deer and smaller animals. In the spring you can hear choruses of tree frogs and in summer, the familiar grunt of bull frogs.

(H) Dan's Bridge

Why is this called Dan’s Bridge?

A small bridge was built here by Dan Rockwell, whose work led to the environmental recovery of the valley. A glacier created the valley during the last ice age some 20,000 years ago. The valley holds the head waters of Brothers Brook which flows through the Montgomery Pinetum and into the Mianus River at Cos Cob Harbor. Several years ago, volunteers rebuilt the bridge in stone ensuring that the stream remains protected. Over the years, volunteers have not only maintained the bridge but also dedicated their time to improving the trails throughout the park. Dan’s original bridge is gone but he was proof that one caring person can have an enormous positive impact.

(I) The Cliff

What forces have shaped this rock?

Weathering has sculpted this rock throughout its exposed life. There are two types of weathering: physical and chemical. Physical weathering involves the mechanical breakdown of the rock material. One process is called “frost wedging.” Water seeps into cracks in the rock and freezes, expanding 9% in volume. The expansion creates as much as 28,000 lbs. per square inch of pressure, which is more than 40 times that required to crack granite. Chemical weathering occurs when the rock breaks down as they chemically react with water, oxygen, carbon dioxide and acids. Water serves as an especially good weathering agent. As water passes through the air, it absorbs gases such as carbon dioxide which increases the acidity of the rainfall and further erodes the rock.

(J) The Brothers Brook Dam

What effect has this dam had on the environment?

This dam has had a large impact on the surrounding environment. When originally built, it created a lake where a field once stood. Over time, Brothers Brook has deposited rich nutrient soils slowly filling the lake. Several years ago, the lake was drained to protect downstream property owners from a possible dam break. Now, reeds, cattails and the invasive loosestrife have taken over where fish once swam.

(K) Fallen Trees

Why are dead trees left on the ground?

As you walk along Main Road, as with most areas of the park, you will see fallen trees and branches. These may look untidy but they provide an important habitat for all sorts of wildlife. Over time they will rot and form habitat for various animal and insect species and eventually contribute an additional layer of nutrient rich soil.

(L) The Viewpoint

What kinds of trees grow in Mianus River Park?

The lookout point offers a tree top view of the river. The majority of the trees are hardwoods such as oak, maple and beech making the park a southern New England hardwood forest.

What animals live in the Park?

While chipmunks, grey squirrels and deer are the most common residents, red foxes, rabbits, skunks, raccoons and even coyotes can be spotted. Wood thrushes, owls, hawks, woodpeckers and chickadees are the more common birds to be found. During the summer, herons can be spotted on the river. Over twenty varieties of warbler are known to nest in the area.

(M) Vernal Pool

Why is a vernal pool important?

Vernal pools are highly productive wetlands that produce a unique assemblage of species, including mole salamanders, wood frogs, and fairy shrimp. These creatures cannot reproduce unless they have access to vernal pools for breeding and for the development of their offspring.

Vernal pools are seasonal bodies of water that attain maximum depths in spring or fall. They fill with spring snowmelt or runoff (“ver” means “spring” in Latin), or are fed by groundwater sources. Some fill in the fall as the groundwater table rises. Size of the pools is generally small – less than 2 acres in area. They lack permanent surface water connections with other wetlands or water bodies, and as a result of periodic drying, they lack fish populations. Vernal pool amphibian eggs and larvae are extremely vulnerable to fish predation.

We hope the Nature Trail has provided a fun and informative introduction to the Mianus River Park.