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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Mount Greylock (north side)

7797.9 m · net rise 524.7 m · total ascent 533.4 m · overall 6.7% · evidence quality B (good) · North Adams · Massachusetts ·

Shape: sustained — 33% of the climbing sits in a quarter of the distance; longest continuous stretch at 10%+ is 208 m.

Matches: BUMPS / Greylock Hillclimb — 2026 BUMPS calendar; the race climbs from North Adams (Notch Road side).

≈ Overhead cover (tree canopy or structures) spans 40% 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?

WindowMaximumLocated at
2 m (diagnostic)≈17%419–421 munder overhead cover
3 m (diagnostic)≈17%1505–1508 munder overhead cover
5 m≈17%1503–1508 munder overhead cover
10 m≈17%1498–1508 munder overhead cover
20 m≈16.4%1491–1511 munder overhead cover
25 m≈16.2%1488–1513 munder overhead cover
50 m≈15.6%1477–1527 munder overhead cover
100 m≈14.9%555–655 munder overhead cover

Measured on the mapped road line; moving the line 1 m either way reads 16.2–16.3% over 25 m.

may start earlier 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: paved throughout, according to each state's road inventory.

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 USGS (public domain)

Mount Greylock (north side) LiDAR hillshade map with contours

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).

Mount Greylock (north side) elevation profile
Mount Greylock (north side) rolling gradient profile
 

Measurement card

ElevationUSGS 3DEP (The National Map) — USGS 3DEP 1 m DEM, MA_Western_B24 (collected 2023-24)
Resolution / CRS1.0 m grid, EPSG:26918; sampled every 1.0 m, bilinear interpolation
Tilesx65y473
Road centreline/mnt/HC_Volume_106727764/site-corpus-fresh/us/mount-greylock-north-side/mount-greylock-north-side.geojson
Quality statusevidence quality B; caveated windows: canopy or structure
AnalysisOCL 0.1.0, analysis 0.1.0, run canopy-all-260903, calculated 2026-09-03

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:26918",
  "elevation_resolution_m": 1.0,
  "elevation_tiles": [
    "data/cache/usa/ma/USGS_1M_18_x65y473_MA_Western_B24.tif"
  ],
  "calculated_at": "2026-09-03T19:08:33+00:00",
  "road_source": "/mnt/HC_Volume_106727764/site-corpus-fresh/us/mount-greylock-north-side/mount-greylock-north-side.geojson",
  "run_id": "canopy-all-260903",
  "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, MA_Western_B24 (collected 2023-24)",
  "elevation_tile_ids": [
    "x65y473"
  ],
  "climb_origin": "discovered",
  "canopy_source": {
    "kind": "ept_corridor_max_return",
    "ept_source": "https://usgs-lidar-public.s3-us-west-2.amazonaws.com/USGS_LPC_MA_ME_MA_QL2_UTM18_L1_2015_LAS_2018",
    "ept_crs": "EPSG:3857",
    "station_coverage": 0.997,
    "cell_ground_m": 1.0,
    "nodes_failed": 0
  },
  "license": "ODbL-1.0",
  "license_url": "https://howsteep.org/licensing"
}