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Mount Washington Auto Road

12030.0 m · net rise 1420.0 m · total ascent 1423.9 m · overall 11.8% · evidence quality B (good) · Greens Grant · New Hampshire · share

Shape: sustained — 28% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 1082 m.

Matches: BUMPS / Mt. Washington Auto Road Bicycle Hillclimb — Series marquee event, run since 1973; 2026 BUMPS calendar.

≈ Overhead cover (tree canopy or structures) spans 9% of this route — detected by comparing the surface model (DSM, treetops and rooftops) against the terrain model (DTM, bare ground). Under cover the bare-ground model is built from fewer laser returns, so metre-scale readings can wobble; maxima whose window sits in a covered zone are marked ≈ below — less certain — the flag does not say whether the true value is higher or lower. Longer windows average over more clean ground and are steadier.

Gradient ladder what do windows mean?

Measured on the mapped road line; moving the line 1 m either way reads 21.4–26.1% over 25 m.

may start earliermay continue beyond end Extent detection suggests reviewing where this climb starts/ends.

Map

Check this route yourself: Google Maps route via their router · Street View at the base where coverage exists · OSM way 90113715 highlights the mapped road · geojson.io our exact measured line · OpenTopoMap

This climb's data: OCL JSON — the full gradient ladder, quality flags and provenance in the OpenClimb Ladder format.

Surface: unpaved throughout, according to each state's road inventory.

Access: Toll road: motor vehicles pay; bicycles — charge unknown (OpenStreetMap toll tags, 2026-09-15).

Measured, not vetted. This page records what the laser record shows about the road's shape — nothing more. Nobody has necessarily ridden or inspected this road for the survey, and a page here is not a recommendation and no guarantee that the road is open, surfaced, rideable or safe. Gates, private sections, missing rights of way and hazards do not show up in elevation data. Check access and conditions on the ground and make your own judgment.

Ridden it, or know better? Submit data for this climb no account needed · Share this climb

Load the interactive map

Route colour = gradient over a 25 m window: <10% 10–20% 20–25% ≥25%

Topo (contours) Vector Aerial   © OpenStreetMap contributors · topo tiles © OpenTopoMap (CC-BY-SA) · vector tiles OpenFreeMap · aerial imagery USGS (public domain)

Profile

The profile and gradient chart share one position — move your pointer over them and the marker follows. Colors are the gradient bands; the shaded span is the steepest 25 m. Any 25 m figure is good to about a point either way (why).

 

Reported values vs. measurement

Measurement card

Provenance

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  "diagnostic_windows_m": [
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  "elevation_crs": "EPSG:26919",
  "elevation_resolution_m": 1.0,
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  ],
  "calculated_at": "2026-08-22T14:11:09+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
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    "1211919721": "2023-11-20 11:49:44+00:00",
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    "1211919719": "2024-10-28 10:11:41+00:00",
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  "osm_pbf_path": "data/cache/pbf/new-hampshire-260822.osm.pbf",
  "osm_snapshot": "2026-08-21T20:21:11Z",
  "elevation_provider": "USGS 3DEP (The National Map)",
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  "elevation_dataset": "USGS 3DEP 1 m DEM, NH_Umbagog_LiDAR_2016_D16 (collected 2016)",
  "elevation_tile_ids": [
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