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Gramstølen

2653.8 m · net rise 265.5 m · total ascent 267.7 m · overall 10.0% · evidence quality B (good) · Lærdal · Vestland

Shape: sustained — 30% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 357 m.

Found purely from mapping and LiDAR data, and not yet matched against books, race records or lists — it may be well known to locals under a name we've never heard. It was cross-checked against the NVDB road network, OpenStreetMap and a second terrain model, but a discovery can still be an artifact of the terrain model or the map. Treat it as a well-evidenced hypothesis until someone has ridden it. If you know this road, tell us what you found — photographs, corrections and local knowledge all welcome; the map links below let you scout it first.

Gradient ladder what do windows mean?

WindowMaximumLocated at
2 m (diagnostic)≈22%2600–2602 munder overhead cover terrain reads 74.7% at 0–2 m across a structure — excluded
3 m (diagnostic)≈21%2599–2602 munder overhead cover terrain reads 73.6% at 0–3 m across a structure — excluded
5 m≈20%2152–2157 munder overhead cover terrain reads 69.6% at 0–5 m across a structure — excluded
10 m≈19%2150–2160 munder overhead cover terrain reads 39.7% at 0–10 m across a structure — excluded
20 m≈18.1%2148–2168 munder overhead cover terrain reads 21.9% at 0–20 m across a structure — excluded
25 m≈17.4%2143–2168 munder overhead cover terrain reads 18.3% at 0–25 m across a structure — excluded
50 m15.3%2250–2300 m
100 m≈14.7%2242–2342 munder overhead cover

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 · 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 (97% unpaved), according to NVDB, Norway's National Road Database: paved for the first 89 m; unpaved from 89 m to 2,450 m; off the road model from 2,450 m to the top. The steepest 25 m lies on the unpaved part.

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 ·

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

Route line = the road surface as the LiDAR survey finds it. Basemap roads are for orientation and may sit a few metres off.

  © OpenStreetMap contributors · topo tiles © OpenTopoMap (CC-BY-SA) · vector tiles OpenFreeMap

Gramstølen LiDAR hillshade map with contours

Profile

The map, 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).

Gramstølen elevation profile
Gramstølen rolling gradient profile
 

Measurement card

ElevationKartverket NHM DTM 1 m (laser-covered ground only) — Nasjonal høydemodell (NHM) DTM, 1 m, EPSG:25833, NN2000 (Kartverket), served by the hoydedata.no ImageServer; ground without a laser project is a coarser resampled product and is never measured
Resolution / CRS1.0 m grid, EPSG:25833; sampled every 1.0 m, bilinear interpolation
TilesE125000-N6794500, E125000-N6795000, E125500-N6794500, E125500-N6795000, E126000-N6794500, E126000-N6795000
Road centrelineOpenStreetMap (local PBF extract)
Quality statusevidence quality B; caveated windows: structure excluded, structure excluded min, texture excluded, texture excluded min
AnalysisOCL 0.1.0, analysis 0.1.0, run no-b06, calculated 2026-10-03

Provenance

{
  "analysis_version": "0.1.0",
  "run_manifest": {
    "manifest_version": "1",
    "code_git_sha": "368c60c29e47d4b421849c953b172a04f7694146",
    "code_git_dirty": "false",
    "analysis_version": "0.1.0",
    "analysis_config_digest": "sha256:8c94015b54267da4",
    "python": "3.14.4",
    "numpy": "2.5.3",
    "rasterio": "1.5.2",
    "pyproj": "3.8.0",
    "laspy": "2.7.0",
    "shapely": "2.1.2",
    "pyosmium": "4.3.1",
    "libosmium": "2.23.1",
    "gdal": "3.12.2",
    "proj": "9.8.1",
    "run_id": "no-b06",
    "road_pbf": "no-b06-block-batch-no-b06.osm.pbf",
    "region_key": "norway",
    "crs": "EPSG:25833",
    "elevation_provider_key": "nhm-no",
    "tile_index": "nhm-window",
    "authority": "nvdb",
    "registry_pbf": "norway-2026-10-01.osm.pbf"
  },
  "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
  ],
  "scale_correction": "point",
  "scale_correction_crs": "EPSG:25833",
  "elevation_crs": "EPSG:25833",
  "elevation_resolution_m": 1.0,
  "elevation_tiles": [
    "data/cache/no/nhm-no_dtm_E125000-N6794500_1m.tif",
    "data/cache/no/nhm-no_dtm_E125000-N6795000_1m.tif",
    "data/cache/no/nhm-no_dtm_E125500-N6794500_1m.tif",
    "data/cache/no/nhm-no_dtm_E125500-N6795000_1m.tif",
    "data/cache/no/nhm-no_dtm_E126000-N6794500_1m.tif",
    "data/cache/no/nhm-no_dtm_E126000-N6795000_1m.tif"
  ],
  "calculated_at": "2026-10-03T19:42:25+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_pbf_path": "data/cache/pbf/no-b06-block-batch-no-b06.osm.pbf",
  "osm_snapshot": "",
  "run_id": "no-b06",
  "elevation_provider": "Kartverket NHM DTM 1 m (laser-covered ground only)",
  "elevation_licence": "CC BY 4.0 \u2014 \u00a9 Kartverket (https://www.kartverket.no/api-og-data/vilkar-for-bruk)",
  "elevation_dataset": "Nasjonal h\u00f8ydemodell (NHM) DTM, 1 m, EPSG:25833, NN2000 (Kartverket), served by the hoydedata.no ImageServer; ground without a laser project is a coarser resampled product and is never measured",
  "elevation_vertical_datum": "NN2000",
  "elevation_tile_ids": [
    "E125000-N6794500",
    "E125000-N6795000",
    "E125500-N6794500",
    "E125500-N6795000",
    "E126000-N6794500",
    "E126000-N6795000"
  ],
  "elevation_blocks": [
    "nhm-dtm-1m"
  ],
  "nhm_laser_projects": [
    {
      "last_flight_date": "2022-08-14",
      "name": "L\u00e6rdal 10pkt 2022",
      "points_per_m2": 10,
      "resolution_m": 0.25,
      "season": "",
      "year": 2022
    },
    {
      "last_flight_date": "2017-07-20",
      "name": "NDH L\u00e6rdal 5pkt 2017",
      "points_per_m2": 5,
      "resolution_m": 0.25,
      "season": "",
      "year": 2017
    },
    {
      "last_flight_date": "2020-10-14",
      "name": "NDH L\u00e6rdal-Filefjell 2pkt 2020",
      "points_per_m2": 2,
      "resolution_m": 0.5,
      "season": "",
      "year": 2020
    },
    {
      "last_flight_date": "2009-01-01",
      "name": "Sogn og Fjordane 2009",
      "points_per_m2": 2,
      "resolution_m": 0.5,
      "season": "season-unknown",
      "year": 2009
    }
  ],
  "nhm_last_flight_date": "2022-08-14",
  "nhm_flight_season_unknown": [
    "Sogn og Fjordane 2009"
  ],
  "nhm_retrieved_at": "2026-10-03T18:14:17Z",
  "nhm_note": "laser projects overlapping the route's cells; the mosaic draws on them by its own priority and which project supplied which pixel is not recorded",
  "climb_origin": "discovered",
  "seam_filled_samples": {
    "count": 0,
    "distances_m": []
  },
  "seam_filled_in_maximum": false,
  "structure_own_ways": 2,
  "tunnel_check": "osm tunnel=* ways on 2 own way(s)",
  "tunnel_ranges_m": [],
  "underground_fraction": 0.0,
  "structure_mask_ranges_m": [
    [
      0.0,
      15.0
    ]
  ],
  "carriageway": {
    "stations": 113,
    "stations_resolved": 113,
    "width_median_m": 6.0,
    "width_p10_m": 4.25,
    "width_min_m": 2.25,
    "width_max_m": 12.0,
    "bounded_share": 0.221,
    "unbounded_share": 0.779,
    "confidence_median": 0.0,
    "width_median_bounded_m": 5.0,
    "window_m": [
      2143.0,
      2168.0
    ],
    "width_at_max25_m": 7.75,
    "window_stations": 7,
    "single_track": false,
    "single_track_rule": "PROVISIONAL (2026-09-15): width_p10_m <= 3.0 m with bounded_share >= 0.6; recorded, not a rule",
    "status": "ok",
    "source": "dtm",
    "station_m": 25.0,
    "window_station_m": 5.0,
    "halfwidth_m": 6.0,
    "step_m": 0.25,
    "level_tol_m": 0.12,
    "break_min_m": 0.3,
    "stations_failed": 0,
    "hedge_to_hedge": {
      "stations": 113,
      "stations_resolved": 113,
      "width_median_m": 9.5,
      "width_p10_m": 6.0,
      "width_min_m": 0.5,
      "width_max_m": 12.0,
      "bounded_share": 0.487,
      "unbounded_share": 0.513,
      "confidence_median": 0.0,
      "width_median_bounded_m": 7.5,
      "window_m": [
        2143.0,
        2168.0
      ],
      "width_at_max25_m": 10.0,
      "window_stations": 7,
      "status": "ok",
      "source": "dsm",
      "station_m": 25.0,
      "window_station_m": 5.0,
      "halfwidth_m": 6.0,
      "step_m": 0.25,
      "level_tol_m": 0.5,
      "break_min_m": 0.3,
      "stations_failed": 0
    }
  },
  "license": "ODbL-1.0",
  "license_url": "https://howsteep.org/licensing"
}