The Historic American Landscapes Survey, or HALS, is the federal program for documenting significant historic landscapes in the United States and its territories. If you search for “Historic American Landscape Survey,” the official program name uses the plural: Historic American Landscapes Survey.
HALS records landscapes through measured or interpretive drawings, large-format photography, and written histories. The finished documentation is preserved in the HABS/HAER/HALS Collection at the Library of Congress, where it becomes part of a permanent public archive.
The National Park Service established HALS in 2000 to give landscape history a dedicated national documentation program alongside the Historic American Buildings Survey and Historic American Engineering Record. NPS, the American Society of Landscape Architects, and the Library of Congress formalized HALS as a permanent federal program through a 2010 tripartite agreement.
What does the Historic American Landscapes Survey document?
HALS is broader than formal gardens. NPS identifies subjects that include designed landscapes and public spaces, traditional cultural landscapes, agricultural sites, residential neighborhoods, and other places where land use, design, vegetation, circulation, topography, structures, and cultural practices help explain a landscape’s history.
A HALS project can address an entire landscape or a component of a larger one. The recorded landscape can be urban or rural, public or private, designed or vernacular, intact or altered, endangered or stable. NPS guidance also makes clear that a landscape doesn’t have to be at least 50 years old, listed in the National Register, or nationally significant to be accepted into the HABS/HAER/HALS Collection.
That distinction matters. HALS documentation is an archival record, not a designation. For the separate federal listing and eligibility framework, see Preserve Signal’s guide to the National Register of Historic Places.
What does a HALS record include?
Formal HALS documentation can combine three principal forms of recordation:
- Measured or interpretive drawings that show the landscape’s organization, features, relationships, and historic or existing conditions.
- Large-format archival photographs that document the appearance of the landscape and the features important to understanding its significance.
- Written historical and descriptive data explaining the landscape’s development, physical character, significance, changes over time, and sources.
The exact package depends on the nature and significance of the landscape and the documentation level selected for the project. HALS is meant to explain what is historically valuable about the landscape, not simply produce attractive photographs or a contemporary site plan.
HALS uses three documentation levels
The Secretary of the Interior’s documentation standards organize HABS, HAER, and HALS work into three levels. NPS samples describe the HALS levels this way:
- Level I: an outline-format historical report, large-format photographs, and a sheet set with measured or interpretive drawings.
- Level II: an outline-format historical report, large-format photographs, and reproductions of existing plans when available.
- Level III: a short-format historical report and large-format photographs, with a sketch plan when it helps explain the site or landscape.
The appropriate level should match the landscape’s nature and significance as well as the purpose of the documentation. In Section 106 mitigation, the documentation level should be established through consultation and, when formal HABS/HAER/HALS recordation is intended, with input from the appropriate NPS regional office.
Level I landscape recordation can be technically different from measuring a building elevation. A complex historic landscape may require the team to document topography, circulation, vegetation, spatial relationships, constructed features, and change over time across a large area. HALS drawing guidance specifically addresses tools such as GIS and GPS, and depending on the site and scope, teams may also use field survey, CAD, laser scanning, photogrammetry (including drone-based capture where permitted and appropriate), vegetation inventories, and analysis of historic plans or plantings. Those methods are not automatically required for every Level I project, but they help explain why landscape architects and other specialists can be important to a rigorous graphic record.
HALS, HABS, and HAER are related but different
HALS is one of three National Park Service Heritage Documentation Programs. HABS focuses on architecture and buildings. HAER focuses on engineering, industrial, technological, and infrastructure resources. HALS focuses on landscapes and the relationships among land, design, vegetation, circulation, structures, use, and culture.
A single place can involve more than one program. A historic estate, industrial complex, battlefield, park, campus, or transportation corridor can contain important buildings, engineering works, and landscape systems. Existing HABS or HAER documentation can therefore be cross-referenced in a HALS record when the programs overlap.
For the engineering side of the documentation system, see Preserve Signal’s guide to the Historic American Engineering Record.
HALS isn’t a Cultural Landscape Report or an ordinary survey
HALS is archival documentation. It shouldn’t be confused with a Cultural Landscape Report, which NPS uses as a treatment and management document for a cultural landscape, or with a local historic-resource inventory that identifies and evaluates resources for planning purposes.
Those products can inform one another. A National Register nomination, Cultural Landscape Report, historic resource survey, oral history, historic map, planting plan, or prior research file can provide evidence for HALS documentation. But producing one of those documents doesn’t automatically create a HALS record.
For the role of inventories and field documentation in identification work, see Preserve Signal’s article on the historic resource survey.
How HALS fits into Section 106
HALS can be used as mitigation when a federal undertaking will adversely affect a historic landscape, but Section 106 doesn’t automatically require HALS documentation. The mitigation measures come from the consultation process and are typically documented in a Memorandum of Agreement, Programmatic Agreement, or other agreed resolution of adverse effects.
When formal HALS documentation is stipulated for Section 106 mitigation, NPS directs project teams to contact the regional office serving the state at the beginning of the project. The regional office reviews draft and final mitigation documentation for conformance with HABS/HAER/HALS requirements, coordinates acceptance, and ultimately transmits accepted material through Heritage Documentation Programs to the Library of Congress.
That archival review is distinct from the Section 106 consultation role. The State Historic Preservation Officer (SHPO), or a Tribal Historic Preservation Officer (THPO) where applicable, participates in the Section 106 process, and an MOA or PA may give the SHPO, THPO, or other consulting parties a defined opportunity to review draft historical narratives, photo keys, drawings, or other mitigation deliverables. The exact review sequence depends on the agreement. A SHPO or THPO review therefore does not replace the separate NPS review needed for formal acceptance into the HABS/HAER/HALS Collection.
For the underlying federal review process, see Preserve Signal’s guide to Section 106 and upcoming historic preservation work.
Traditional cultural landscapes can also be documented
HALS isn’t limited to landscapes designed by landscape architects. NPS specifically includes traditional cultural landscapes among the kinds of places the program can record. In those cases, the landscape’s meaning may depend heavily on community knowledge, customary use, patterns of movement, natural features, and relationships that aren’t obvious from a conventional architectural survey.
That doesn’t make HALS and the National Register concept of a traditional cultural place interchangeable. HALS is a documentation program. National Register eligibility is a separate significance and integrity determination, and culturally sensitive information may require careful treatment or confidentiality.
For that separate framework, see Preserve Signal’s article on traditional cultural properties and traditional cultural places.
Three HALS examples in Preserve Signal’s coverage area
HALS records can look very different from one another. These examples from the South and Mid-Atlantic show the program’s range:
- Overhills | North Carolina. HALS NC-3 documents the Overhills Historic District near Fayetteville. The Library of Congress record includes 53 photographs, 13 measured drawings, and 76 data pages describing an estate and hunt-club landscape with ornamental plantings, longleaf pine and wiregrass, equestrian features, fields, and historic circulation patterns.
- Mount Vernon | Virginia. HALS VA-25 documents the landscape at George Washington’s Mount Vernon. The Library of Congress record includes large-format photography of the estate landscape and illustrates how HALS can address nationally important places whose significance extends beyond individual buildings.
- Juliette Gordon Low Birthplace Garden | Georgia. HALS GA-4 documents the Savannah garden associated with the Juliette Gordon Low Birthplace. The record focuses on landscape architect Clermont H. Lee’s 1950s period-garden design and shows how a relatively compact garden can be significant as a designed cultural landscape.
Why HALS can matter as a project signal
For firms tracking preservation work, a HALS requirement can reveal that a project has moved beyond a general recognition of historic value and into a defined documentation or mitigation scope. That can create work for landscape architects, historians, photographers, GIS or graphics specialists, and cultural-resource consultants.
But HALS documentation by itself isn’t proof that construction is imminent. NPS accepts donated documentation from a wide range of sources, including competition entries and student projects, in addition to formal mitigation documentation. The long-running HALS Challenge, supported by NPS and the American Society of Landscape Architects, is one recurring source of competition-based HALS records. A Challenge entry or university studio project can be historically valuable without signaling an active capital project.
By contrast, HALS documentation expressly required in an executed Section 106 Memorandum of Agreement or Programmatic Agreement is tied to resolution of adverse effects from a federal undertaking. For project intelligence, that is a much stronger signal that physical alteration, demolition, or another consequential project action is contemplated, although the documentation requirement alone still does not establish the construction schedule. The strongest signal comes from connecting the HALS requirement with design decisions, agency approvals, funding, property disposition, procurement, or other evidence of the undertaking’s current stage.
For places that include both landscape and built resources, the distinction between a landscape and a historic district can also matter when reading the project record.
The practical takeaway
The Historic American Landscapes Survey is the national archival documentation program for significant historic landscapes. It can record everything from designed gardens and parks to agricultural landscapes, neighborhoods, transportation corridors, and traditional cultural landscapes using standardized written, photographic, and graphic documentation.
If HALS appears in a project file, the useful questions are why the documentation is being prepared, what level is required, who is reviewing it, and what larger project or preservation decision created the need for recordation. Those answers tell you far more than the acronym alone.