From Island to Industrial Powerhouse
Originally a true island, Iona became connected to the mainland in the 19th century when a railroad causeway was built across the marsh. This small change dramatically altered its future.
In the late 1800s, Iona Island became one of the most important naval ammunition depots in the United States. Operated by the United States Navy, the site stored massive quantities of explosives used to supply naval forces.
Because of the dangerous materials stored there, strict rules were enforced. Workers lived on the island under careful supervision, and safety was always a top priority. Despite precautions, a major explosion occurred in 1903, highlighting just how risky the operation was.
During both World Wars, the island played a crucial role in supporting military efforts, quietly contributing to the nation’s defense from its secluded location along the Hudson.
A Dramatic Transformation
After World War II, the need for the ammunition depot declined, and the site was eventually abandoned by the Navy. Nature slowly began to reclaim the land.
Today, Iona Island is part of the Bear Mountain State Park and is managed as a protected wildlife area. What was once a restricted military zone is now a sanctuary for birds and other wildlife.
The surrounding marshlands have become especially important for migratory birds. In fact, the area is recognized as one of the most significant bird habitats along the Hudson River.
A Haven for Wildlife and Quiet Views
Unlike many nearby attractions, Iona Island is not a place for crowds or busy activities. Instead, it offers something quieter—wide marsh views, peaceful water, and the chance to observe nature undisturbed.
Visitors cannot freely walk onto most of the island itself, as it is protected. However, excellent views can be enjoyed from nearby vantage points, especially along the Hudson River shoreline and from overlooks near Bear Mountain.
Birdwatchers often visit the area to spot herons, egrets, and even bald eagles. The stillness of the marsh, combined with the backdrop of surrounding mountains, creates a calm and almost hidden atmosphere.
While access to Iona Island is limited, the surrounding area offers plenty of family-friendly experiences:
- Take a short walk along nearby trails and look out over the marsh—kids will enjoy spotting birds and wildlife
- Bring binoculars for a simple birdwatching adventure
- Visit the Trailside Museums and Zoo to learn more about local animals
- Enjoy a picnic at nearby scenic spots in Bear Mountain State Park
- Combine the visit with a walk across the Bear Mountain Bridge for a full day of exploration
Iona Island may not have the dramatic ruins of a fort or the towering presence of a bridge, but its story is just as compelling. From a bustling naval depot to a protected natural habitat, it reflects the changing relationship between people, industry, and the environment.
For families visiting the Hudson Highlands, it offers something unique—a chance to slow down, look closely, and discover the quieter side of history and nature.
One mile (1.6 km) south of the Bear Mountain Bridge