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Mount Washington Auto Road

12030.0 m · net rise 1420.0 m · total ascent 1423.9 m · overall 11.8% · confidence: good · 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?

Window	Maximum	Located at
2 m (diagnostic)	≈38%	6115–6117 m	under overhead cover terrain reads 113.4% at 10–12 m across a structure — excluded
3 m (diagnostic)	≈32%	639–642 m	under overhead cover terrain reads 88.2% at 10–13 m across a structure — excluded
5 m	≈27%	521–526 m	under overhead cover terrain reads 60.5% at 8–13 m across a structure — excluded
10 m	≈24%	12019–12029 m	under overhead cover terrain reads 30.7% at 4–14 m across a structure — excluded
20 m	22.1%	12009–12029 m
25 m	21.1%	12004–12029 m
50 m	18.7%	9992–10042 m
100 m	17.0%	8315–8415 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.

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

Mount Washington Auto Road LiDAR hillshade map with contours

Profile

Reported values vs. measurement

Source	Claim	Evidence	Best-matching window
Mt. Washington Auto Road Bicycle Hillclimb (race materials)	12%	event_description	100 m (-5.0 pp)

Provenance

{
  "analysis_version": "0.1.0",
  "sample_interval_m": 1.0,
  "interpolation": "bilinear",
  "smoothing": "none",
  "gradient_windows_m": [
    5.0,
    10.0,
    20.0,
    25.0,
    50.0,
    100.0
  ],
  "diagnostic_windows_m": [
    2.0,
    3.0
  ],
  "elevation_crs": "EPSG:26919",
  "elevation_resolution_m": 1.0,
  "elevation_tiles": [
    "data/cache/usa/nh/USGS_1M_19_x31y491_NH_Umbagog_LiDAR_2016_D16.tif",
    "data/cache/usa/nh/USGS_1M_19_x32y491_NH_Umbagog_LiDAR_2016_D16.tif"
  ],
  "calculated_at": "2026-08-22T14:11:09+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_ids": [
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  ],
  "osm_versions": {
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  },
  "osm_timestamps": {
    "90113715": "2024-09-29 18:09:22+00:00",
    "290550835": "2024-09-29 18:09:22+00:00",
    "290550829": "2024-10-28 10:11:41+00:00",
    "1211919720": "2024-10-29 18:44:05+00:00",
    "1211919721": "2023-11-20 11:49:44+00:00",
    "1211919723": "2024-10-28 10:38:06+00:00",
    "1211919719": "2024-10-28 10:11:41+00:00",
    "828959300": "2024-10-28 10:38:06+00:00",
    "962675648": "2024-10-09 18:01:57+00:00",
    "962675647": "2024-10-28 10:38:06+00:00",
    "1322664023": "2024-10-28 10:38:06+00:00",
    "828959301": "2024-10-28 10:38:06+00:00",
    "828959299": "2024-10-28 10:38:06+00:00",
    "18848737": "2024-10-28 10:38:06+00:00"
  },
  "osm_retrieved_at": "2026-08-22T14:10:20+00:00",
  "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)",
  "elevation_licence": "Public domain \u2014 USGS 3DEP 1 m DEM, courtesy of the U.S. Geological Survey",
  "elevation_dataset": "USGS 3DEP 1 m DEM, NH_Umbagog_LiDAR_2016_D16 (collected 2016)",
  "elevation_tile_ids": [
    "x31y491",
    "x32y491"
  ],
  "climb_origin": "named",
  "notes": "ANNEX per settled toll policy - private toll road, BUMPS venue (Mt Washington Hillclimb). 'Highest paved road in the Northeast' folklore; one short 'metal' bridge-deck way mid-route. Chain rebuilt 2026-08-22 by node adjacency (name-scrape had 3 disconnected spurs); ends 116 m from GNIS summit (-71.30333, 44.27059).",
  "canopy_source": {
    "kind": "ept_corridor_max_return",
    "ept_source": "https://s3-us-west-2.amazonaws.com/usgs-lidar-public/NH_Umbagog_2016",
    "ept_crs": "EPSG:3857",
    "station_coverage": 0.991,
    "cell_ground_m": 1.0,
    "nodes_failed": 0
  },
  "license": "ODbL-1.0",
  "license_url": "https://howsteep.org/licensing.html"
}