Frederick C. Mannillo, Jr. Nature Trail

Wheelchair Accessible



The 250 yard trail, designed to showcase a special and unique place, leads to a viewing platform beside a small wetland.

When you traverse this trail you are in the midst of one of the natural habitats of the Florida Keys and are invited to connect with your surroundings.

Focusing one's senses can create a “sense of place."  Allow yourself to become a part of what you are experiencing - the unique pine rocklands of the Florida Keys.

The Beauty & Sense of the Place


Benches offer a place to sit, observe, relax and reflect.  Trail signs explore topics from geologic history to the impacts of recent development. 

Most of the plants are tropical varieties from the Caribbean; the animals are temperate species from the mainland.  The native plants survive severe storms, extended dry periods, salt spray and fire, and provide a home and food for animals and birds.  This combined ecosystem is found nowhere else in the world.

What you see here today is how this area has looked for thousands of years.

The Fauna



The Fauna

As you move along the trail, you might encounter a Key deer, alligator, turtle or snake.  This is their home.  Mammals such as the Key deer and the rarely seen Lower Keys marsh rabbit and silver rice rat have evolved adaptations to the limited island environment, to scarce and salty water and to seasonal storms.

NOTE:  Alligator in photo above is one of the resident gators at The Blue Hole

The Flora



Unlike the animals, which mostly migrated from the mainland during epochs of lowered sea levels, the flora (plants) here are representative of those found on Caribbean islands.  Prevailing winds, water currents and bird migrations afforded easy transport for seeds to the Florida Keys.

Although many of the plants seem to grow from solid rock they are actually growing in small solution holes in the caprock and have developed a dense and compact root ball.  The confinement of the roots may produce a natural bonsai effect and a small tree may actually be quite old.

The Palms



Three main types of palms grow along this trail: the saw palmetto, the thatch palm and the silver palm.

The saw palmetto (Serenoa repens)trunk generally grows along the ground rather than upright and has small spurs along the stem of the leaves.

The thatch palm (Thrinax morrisii)has  pale green leaves whose fingers do not fully divide from each other as they approach the stem. Thatch palms have a fine beard of old root mass which is forced upward as new roots are developed at the base. The white berries of the thatch palm are an important food source for birds, Key deer and other animals. The fronds from these palms were used by Native Americans and early settlers as roofing material.

The silver palm (Coccothrinax argentata) has more slender fingers which divide more fully, and the leaves are darker green on top and silver colored on the underside. 

Poisonwood Trees




The poisonwood (Metopium toxiferum) bush or tree has shiny green ovate shaped leaves (often with little black spots) that are always in opposite pairs except for the single leaf at the end of the branch.

The sap from this tree causes a strong reaction in some people similar to that of poison ivy.  Therefore, remember not to touch the leaves or branches of this tree.

 The fruit of the poisonwood tree supplements the diet of many birds and is a staple food for the threatened White-crowned pigeon. 

A Natural History Journey

The Pine Rocklands



The Florida Keys are not dry rocks surrounded by water.  The Keys are more like rigid sponges where water moves over, under and all around. 

The pine rockland is an open canopy with little underbrush. But if you look carefully in the small solution holes along the trail, you will see thriving colonies of delicate native herbs, orchids and ferns with tiny fruits and flowers, as well as interesting insects, snakes and even fish.

The pine rockland ecosystem combines a caprock substrate with slash pines (Pinus elliottii var. densa). The slash pines were so named because they were slashed to harvest turpentine. These pine rocklands contain more than 250 plant species. The only pine rocklands in the United States are in South Florida; and, only five percent of the original stands survive today.

Eighty percent of the Florida Keys' remaining pine rockland stands are here in the National Key Deer Refuge.

The pine forests need periodic fire to retain their unique identity. The pines have a deep tap root to anchor their tall structures and to reach down to the fresh water lens. Even the dead trees can stay upright for years, serving as feeding areas for woodpeckers and observation posts for hawks and vultures.

When dead trees finally succumb to ants, termites and weather, decomposition is rapid leaving little debris on the forest floor.  The nutrients are soon recycled and do not remain to accumulate in the soil as in temperate northern ecosystems.

Geology & Hydrology



Beneath this trail is a 100,000 year old coral reef created when this area was more than 20 feet under water. About 80,000 years ago glaciers bound up so much water that the sea level dropped about 400 feet.  The exposed reef died and fossilized. By 10,000 years ago the glaciers had again receded and the sea level had risen to create the Florida we know today.

The Florida Keys are composed of this fossilized reef.  Starting in the Lower Keys, on Big Pine Key, the reef dives deeper and is overlaid with Miami oolite (sediments of lime deposited layer by layer on top of the ancient reef).  This is the exposed caprock seen along the trail.  Slightly acidic rainwater slowly dissolves the caprock, creating solution holes.


The Florida Keys have no rivers or streams; rainfall is the only natural source of fresh water.  On Big Pine Key a fresh water lens floats on top of the underlying salt water table. This fresh water lens makes possible the unique plant and animal communities found here and is why the Key deer herd is centered on Big Pine Key.

The Trail Construction & Location



The Frederick C. Mannillo, Jr. Wheelchair Accessible Nature Trail is on Key Deer Boulevard,  a short distance past the Blue Hole. 

Trail Construction

Volunteers from the Key Deer Protection Alliance, the National Key 

Deer Refuge, the local community, AmeriCorps, and the Youth Conservation Corp designed, developed and constructed the trail.

Donations to a memorial fund administered by the Key Deer Protection Alliance. Inc. and a matching grant from the U.S. Fish and Wildlife Service made its construction possible.

The trail is paved with an emulsified gravel to form a hard and durable, yet natural appearing, surface to assist visitors using a wheelchair.


In memory of Frederick C. Mannillo, Jr.

1948 - 1996

An articulate, persistent, effective voice for the conservation and preservation of the environment.