LIVING SURVEY — measurements are reviewed continuously as new data and local evidence arrive. Seen a sign, a gate, or a better name? Submit an update no account needed · photos welcome via GitHub

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Chapfli

7269.2 m · net rise 1191.5 m · total ascent 1238.3 m · overall 16.4% · evidence quality U (needs confirmation) · Sachseln · Obwalden ·

Shape: sustained — 40% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 1255 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 swisstopo’s swissTLM3D road model, 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.

needs review max5 over 45, max10 over 40 — treat short-window maxima here as provisional.

Gradient ladder what do windows mean?

WindowMaximumLocated at
2 m (diagnostic)≈55%3346–3348 munder overhead cover terrain reads 165.7% at 6411–6413 m across a structure — excluded
3 m (diagnostic)≈51%2010–2013 munder overhead cover terrain reads 117.6% at 6411–6414 m across a structure — excluded
5 m≈45%2735–2740 munder overhead cover terrain reads 95.8% at 6396–6401 m across a structure — excluded
10 m≈42%2734–2744 munder overhead cover terrain reads 70.9% at 1551–1561 m across a structure — excluded
20 m≈38.8%1405–1425 munder overhead cover terrain reads 59.8% at 1360–1380 m across a structure — excluded
25 m≈38.3%1400–1425 munder overhead cover terrain reads 54.4% at 1355–1380 m across a structure — excluded
50 m≈36.9%2694–2744 munder overhead cover terrain reads 44.9% at 1406–1456 m across a structure — excluded
100 m≈34.6%2685–2785 munder overhead cover terrain reads 41.4% at 1356–1456 m across a structure — excluded

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: mixed (53% unpaved), according to swisstopo's swissTLM3D road model: paved for the first 1,051 m; unpaved from 1,051 m to 3,540 m; paved from 3,540 m to 5,866 m; unpaved from 5,866 m to 7,216 m. The steepest 25 m lies on the unpaved part.

Access: Listed 2026-09-11 (record-class scrutiny, Peter): this page's steepest 25 m meets or exceeds the Baldwin Street mark (34.8 %). A figure that would beat the recognised records is treated with special scepticism: it stays out of the rankings until a person has passed it on the aerial, the road authority's line and the detector battery, as Ffordd Pen Llech and one Welsh lane were. Also trimmed 2026-09-15 at the tail dog-leg (a driveway, Peter's ruling); steepest 25 m now 38.3 %.

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%

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

Chapfli 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).

Chapfli elevation profile
Chapfli rolling gradient profile
 

Measurement card

Elevationswisstopo swissALTI3D — swissALTI3D 0.5 m DTM (Federal Office of Topography swisstopo)
Resolution / CRS0.5 m grid, EPSG:2056; sampled every 1.0 m, bilinear interpolation
Tiles2659-1189, 2660-1187, 2660-1188, 2660-1189, 2661-1187, 2661-1188, 2662-1187
Road centrelineOpenStreetMap (local PBF extract), snapshot 2026-09-09T20:21:20Z
Quality statusevidence quality U; review flags: max5 over 45, max10 over 40
AnalysisOCL 0.1.0, analysis 0.1.0, run retro-260915-dogleg-all, calculated 2026-09-15

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:2056",
  "elevation_resolution_m": 0.5,
  "elevation_tiles": [
    "data/cache/ch/swissalti3d_2022_2659-1189_0.5_2056_5728.tif",
    "data/cache/ch/swissalti3d_2022_2660-1187_0.5_2056_5728.tif",
    "data/cache/ch/swissalti3d_2022_2660-1188_0.5_2056_5728.tif",
    "data/cache/ch/swissalti3d_2022_2660-1189_0.5_2056_5728.tif",
    "data/cache/ch/swissalti3d_2022_2661-1187_0.5_2056_5728.tif",
    "data/cache/ch/swissalti3d_2022_2661-1188_0.5_2056_5728.tif",
    "data/cache/ch/swissalti3d_2022_2662-1187_0.5_2056_5728.tif"
  ],
  "calculated_at": "2026-09-15T21:30:24+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_pbf_path": "data/cache/pbf/switzerland-2026-09-10.osm.pbf",
  "osm_snapshot": "2026-09-09T20:21:20Z",
  "run_id": "retro-260915-dogleg-all",
  "elevation_provider": "swisstopo swissALTI3D",
  "elevation_licence": "swisstopo open government data (OGD): free use, attribution '\u00a9 swisstopo' \u2014 https://www.swisstopo.admin.ch/en/terms-and-conditions",
  "elevation_dataset": "swissALTI3D 0.5 m DTM (Federal Office of Topography swisstopo)",
  "elevation_tile_ids": [
    "2659-1189",
    "2660-1187",
    "2660-1188",
    "2660-1189",
    "2661-1187",
    "2661-1188",
    "2662-1187"
  ],
  "climb_origin": "discovered",
  "canopy_check": "unavailable \u2014 no surface model (DSM or point cloud) registered for this coverage",
  "structure_own_ways": "none \u2014 the route carried no way list; own decks unmasked",
  "structure_mask_ranges_m": [
    [
      0.0,
      15.0
    ],
    [
      600.6,
      630.6
    ],
    [
      464.1,
      494.1
    ],
    [
      369.5,
      399.5
    ],
    [
      372.9,
      402.9
    ],
    [
      391.7,
      421.7
    ],
    [
      436.6,
      466.6
    ],
    [
      627.5,
      657.5
    ]
  ],
  "license": "ODbL-1.0",
  "license_url": "https://howsteep.org/licensing"
}