How BoatLaunchMap Verifies Boat Ramp Data
Last updated: May 17, 2026
Source hierarchy
Every boat ramp in our directory is attributed to the most authoritative source we have for that record. When multiple sources describe the same physical location we prefer them in this order:
- The state agency that manages the ramp (e.g. NY DEC, FL FWC, MN DNR).
- Federal agencies (US Army Corps of Engineers, USGS, USFWS, BLM, NPS, US Forest Service).
- Google Places — used to enrich addresses, hours, photos, and user ratings.
- OpenStreetMap — used to fill gaps where no authoritative source has yet been integrated.
- User submissions — accepted only after coordinate and identity verification.
Per-record attribution
Each ramp page lists every source that contributed data for that specific record and links directly to the dataset where you can verify the original. State-agency records carry a Maintained by citation naming the operating government organization. This citation is also emitted in the page’sschema.org/TouristAttraction JSON-LD as themaintainer property and in the sameAs array, so search engines and language models can verify provenance.
Authoritative state and federal sources
| Agency | Jurisdiction | Records |
|---|---|---|
| Florida Fish and Wildlife Conservation Commission (FWC) | Florida | ~2,600 |
| Minnesota Department of Natural Resources | Minnesota | ~3,000 |
| Wisconsin Department of Natural Resources | Wisconsin | ~3,100 |
| Michigan Department of Natural Resources | Michigan | ~1,300 |
| New York State Department of Environmental Conservation | New York | ~900 |
| Washington Department of Fish and Wildlife | Washington | ~470 |
| Massachusetts Office of Fishing and Boating Access | Massachusetts | ~280 |
| Virginia Department of Wildlife Resources | Virginia | ~230 |
| North Carolina Wildlife Resources Commission | North Carolina | ~400 |
| South Carolina Department of Natural Resources | South Carolina | ~230 |
| Georgia Department of Natural Resources | Georgia | ~400 |
| Connecticut Department of Energy and Environmental Protection | Connecticut | ~120 |
| United States Geological Survey (USGS) | Federal | ~500 |
Deduplication
The same physical ramp often appears in multiple sources (OpenStreetMap, Google Places, and a state agency, for example). We cluster records whose GPS coordinates fall within 40 metres (~130 feet) of each other and merge them into a single authoritative record, preferring the state agency’s name and the richest set of available fields. As of May 2026 this process consolidated approximately 4,000 duplicate clusters and removed approximately 5,000 redundant rows.
Freshness
State datasets are refreshed on each agency’s published cadence (typically annual to quarterly). Each ramp page shows a Last verified timestamp reflecting the most recent time its core fields were re-checked against an authoritative source. This date is also emitted in the JSON-LD dateModified property.
Coverage gaps
States where we have not yet integrated an authoritative agency dataset are populated from OpenStreetMap and Google Places only. These ramps will not show a Maintained by citation; the Sources line will list only community-contributed origins. We add new state and federal sources on a rolling basis.
Report a correction
If you find a record that conflicts with the operating agency’s current information, please report it via the contact page. Corrections that can be verified against an agency record are applied within one update cycle.