100K+ Historic Places and the Infrastructure Data Hiding in Plain Sight

There are over 100,000 places in the United States listed on the National Register of Historic Places — yet most Americans couldn't name five of them outside their own state. There are 88,000 dams across the country, many of them aging and in need of repair, but the data about their condition is buried in Army Corps of Engineers databases that few people know exist. HeritageIndex.org brings these overlooked infrastructure and heritage datasets into the open across 5 searchable platforms.

100,000+ Historic Places

The historic places database contains over 100,000 listings from the National Register of Historic Places, maintained by the National Park Service. This includes everything from architecturally significant buildings and archaeological sites to historic districts and cultural landscapes that tell the story of American history.

Each listing includes the property name, location, date of listing, significance criteria, and the period of significance — the era from which the property derives its historical importance. Users can search by state, county, or city, making it easy to discover historic resources in their own community or in places they plan to visit.

The National Register is more than a tourist guide. Listing on the register qualifies property owners for federal preservation tax incentives and grants, makes properties eligible for consideration in federal project planning, and provides a formal recognition of historical significance that can influence local zoning and development decisions. Yet the National Park Service's own database interface makes it difficult to search, filter, or analyze this data at scale. HeritageIndex changes that by providing modern search capabilities and geographic browsing.

88,000 Dams: America's Aging Infrastructure

The dams database indexes 88,000 dams from the National Inventory of Dams (NID), maintained by the U.S. Army Corps of Engineers. Every dam in the country — from massive hydroelectric installations on the Columbia River to small earthen dams on private land — is cataloged with its location, owner, purpose, height, storage capacity, and hazard classification.

The hazard classification is perhaps the most important data point. Dams are classified as high hazard (failure would cause loss of life), significant hazard (failure would cause economic damage), or low hazard. The American Society of Civil Engineers has repeatedly given America's dam infrastructure a near-failing grade, citing the thousands of high-hazard dams that are deficient and the billions of dollars needed for repairs.

HeritageIndex makes this data accessible to communities living downstream of aging dams. When a dam's condition data is buried in an Army Corps database that requires specialist knowledge to navigate, communities can't advocate effectively for repairs or emergency planning. When the same data is searchable by location with clear hazard classifications, residents can find dams near their homes and understand the risks they face. This is infrastructure transparency at its most fundamental — helping people understand threats to their safety that exist in plain sight.

51,000 Fire Stations

The fire stations directory catalogs 51,000 fire stations across the United States from FEMA's National Fire Department Registry. Each listing includes the department name, station address, type of department (career, volunteer, combination), and contact information.

This data serves multiple audiences. Homeowners and insurance companies use fire station proximity as a factor in property insurance ratings — the closer a home is to a fire station, the lower the insurance premium. Home buyers evaluating neighborhoods can check fire protection coverage. Researchers studying public safety infrastructure can analyze the distribution of fire services relative to population density, identifying communities that may be underserved.

The volunteer vs. career distinction is particularly telling. In many rural areas, fire protection depends entirely on volunteer departments, which face growing recruitment challenges as demographics shift and working patterns change. Mapping these departments helps communities and policymakers understand where volunteer fire protection may be at risk and where professional services might need to expand.

30,000 Museums

The museums directory indexes 30,000 museums across the country, sourced from the Institute of Museum and Library Services (IMLS) Museum Universe Data File. The collection encompasses art museums, history museums, science centers, children's museums, botanical gardens, zoos, nature centers, and historic houses — the full spectrum of institutions dedicated to preserving and presenting cultural, scientific, and historical heritage.

Each listing includes the museum's name, type, location, revenue, and income information. Users can search by type and location to find museums near them, discover institutions they didn't know existed, or plan cultural excursions when traveling. The data also supports research into the museum sector — how institutions are distributed across urban and rural areas, how revenue varies by type and region, and which communities have the richest cultural infrastructure.

Making Infrastructure Visible

The datasets in HeritageIndex share a common thread: they all describe physical infrastructure — built, maintained, and often neglected — that shapes daily life in communities across America. Historic places anchor community identity. Dams control flood waters and store drinking water. Fire stations provide emergency response. Museums preserve collective memory. Yet the data about these assets is scattered across federal agencies, formatted for specialists, and effectively invisible to the public they serve.

Visit HeritageIndex.org to explore historic places in your state, check dam safety data near your home, find fire stations and museums, and discover the infrastructure data hiding in plain sight.

HeritageIndex is one of the infrastructure data platforms built by TheDataProject.AI — making heritage and infrastructure data searchable, visible, and accessible to everyone.