# U.S. Geological Survey Altitude Datums API

**Canonical:** https://apis.io/apis/u-s-geological-survey/u-s-geological-survey-altitude-datums-api/  
**Provider:** U.S. Geological Survey — https://apis.io/providers/u-s-geological-survey/  
**Base URL:** https://earthquake.usgs.gov/fdsnws/event/1  
**Documentation:** https://www.usgs.gov/tools/asset-identifier-service-ais

U.S. Geological Survey Altitude Datums API is one of 47 APIs that [U.S. Geological Survey](https://apis.io/providers/u-s-geological-survey/) publishes on the [APIs.io](https://apis.io/) network, described by a machine-readable OpenAPI specification. This API exposes 3 JSON Schema definitions. Tagged areas include altitude-datums. The published artifact set on APIs.io includes an OpenAPI specification, API documentation, a getting-started guide, a JSON-LD context, authentication docs, and 3 JSON Schemas.

The recommended vertical datum is NAVD88 (North American Vertical Datum of 1988) where applicable as stated in Office of Information Technical Memo 2002.01. NGVD29 (National Geodetic Vertical Datum of 1929) and NAVD88 are the only datums that can be converted on output. NWIS uses the North American Vertical Datum Conversions (VERTCON) of the National Geodetic Survey to convert from NGVD29 to NAVD88 or vice versa. Conversions to or from other vertical datums are not available.

## Operations (8)

| Method | Path | Summary |
|---|---|---|
| GET | `/collections/altitude-datums` | Get Altitude datums metadata |
| GET | `/collections/altitude-datums/items` | Get Altitude datums items |
| OPTIONS | `/collections/altitude-datums/items` | Options for Altitude datums items |
| POST | `/collections/altitude-datums/items` | Get Altitude datums items with CQL2 |
| GET | `/collections/altitude-datums/items/{featureId}` | Get Altitude datums item by id |
| OPTIONS | `/collections/altitude-datums/items/{featureId}` | Options for Altitude datums item by id |
| GET | `/collections/altitude-datums/queryables` | Get Altitude datums queryables |
| GET | `/collections/altitude-datums/schema` | Get Altitude datums schema |

## Machine-readable artifacts (13)

- **OpenAPI** — https://raw.githubusercontent.com/api-evangelist/u-s-geological-survey/refs/heads/main/openapi/u-s-geological-survey-altitude-datums-api-openapi.yml
- **Conformance** — https://raw.githubusercontent.com/api-evangelist/u-s-geological-survey/refs/heads/main/conformance/u-s-geological-survey-conformance.yml
- **Documentation** — https://earthquake.usgs.gov/fdsnws/event/1/
- **GettingStarted** — https://earthquake.usgs.gov/earthquakes/feed/
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/u-s-geological-survey/refs/heads/main/json-schema/usgs-earthquake-api-earthquake-properties-schema.json
- **JSONLD** — https://raw.githubusercontent.com/api-evangelist/u-s-geological-survey/refs/heads/main/json-ld/usgs-earthquake-api-context.jsonld
- **Examples** — https://raw.githubusercontent.com/api-evangelist/u-s-geological-survey/refs/heads/main/examples/usgs-earthquake-api-earthquake-properties-example.json
- **Documentation** — https://api.waterdata.usgs.gov/docs/
- **Authentication** — https://api.waterdata.usgs.gov/signup/
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/u-s-geological-survey/refs/heads/main/json-schema/usgs-water-data-api-monitoring-location-properties-schema.json
- **JSONSchema** — https://raw.githubusercontent.com/api-evangelist/u-s-geological-survey/refs/heads/main/json-schema/usgs-water-data-api-time-series-properties-schema.json
- **JSONLD** — https://raw.githubusercontent.com/api-evangelist/u-s-geological-survey/refs/heads/main/json-ld/usgs-water-data-api-context.jsonld
- **Examples** — https://raw.githubusercontent.com/api-evangelist/u-s-geological-survey/refs/heads/main/examples/usgs-water-data-api-monitoring-location-properties-example.json

## Other U.S. Geological Survey APIs (12)

- [USGS Water Data APIs](https://apis.io/apis/u-s-geological-survey/water-data-ogc-api/)
- [Asset Identifier Service (AIS)](https://apis.io/apis/u-s-geological-survey/asset-identifier-service-ais/)
- [Seismic Design Web Service](https://apis.io/apis/u-s-geological-survey/seismic-design-web-service/)
- [ScienceBase](https://apis.io/apis/u-s-geological-survey/sciencebase/)
- [StreamStats Web Services](https://apis.io/apis/u-s-geological-survey/streamstats-web-services/)
- [USGS Water Services (Legacy)](https://apis.io/apis/u-s-geological-survey/usgs-water-services/)
- [U.S. Geological Survey Catalog API](https://apis.io/apis/u-s-geological-survey/u-s-geological-survey-catalog-api/)
- [U.S. Geological Survey Earthquakes API](https://apis.io/apis/u-s-geological-survey/u-s-geological-survey-earthquakes-api/)
- [U.S. Geological Survey Monitoring Locations API](https://apis.io/apis/u-s-geological-survey/u-s-geological-survey-monitoring-locations-api/)
- [U.S. Geological Survey Reference Data API](https://apis.io/apis/u-s-geological-survey/u-s-geological-survey-reference-data-api/)
- [U.S. Geological Survey Time Series Data API](https://apis.io/apis/u-s-geological-survey/u-s-geological-survey-time-series-data-api/)
- [U.S. Geological Survey Agency Codes API](https://apis.io/apis/u-s-geological-survey/u-s-geological-survey-agency-codes-api/)

## Tags

altitude-datums

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