{
 "ocl_version": "0.1.0",
 "name": "Calhoun Hill Road",
 "slug": "calhoun-hill-road-2",
 "confidence": "A",
 "reported_claims": [],
 "ladder": [
  {
   "window_m": 2.0,
   "max_gradient_pct": 21.807961873804516,
   "diagnostic": true,
   "flags": [],
   "start_distance_m": 40.0,
   "end_distance_m": 42.0,
   "start_elevation_m": 182.1193038452006,
   "end_elevation_m": 182.55546308267668,
   "min_gradient_pct": -2.5653113947967654
  },
  {
   "window_m": 3.0,
   "max_gradient_pct": 22.57287659017398,
   "diagnostic": true,
   "flags": [],
   "start_distance_m": 40.0,
   "end_distance_m": 43.0,
   "start_elevation_m": 182.1193038452006,
   "end_elevation_m": 182.7964901429058,
   "min_gradient_pct": -2.391592789000659
  },
  {
   "window_m": 5.0,
   "max_gradient_pct": 20.852393190823477,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 1122.0,
   "end_distance_m": 1127.0,
   "start_elevation_m": 296.10095150290914,
   "end_elevation_m": 297.1435711624503,
   "min_gradient_pct": -2.176579559380798
  },
  {
   "window_m": 10.0,
   "max_gradient_pct": 20.58893756325233,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 1117.0,
   "end_distance_m": 1127.0,
   "start_elevation_m": 295.0846774061251,
   "end_elevation_m": 297.1435711624503,
   "min_gradient_pct": -1.942210695131621
  },
  {
   "window_m": 20.0,
   "max_gradient_pct": 20.158102300872827,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 1107.0,
   "end_distance_m": 1127.0,
   "start_elevation_m": 293.11195070227575,
   "end_elevation_m": 297.1435711624503,
   "min_gradient_pct": -1.727324227390028
  },
  {
   "window_m": 25.0,
   "max_gradient_pct": 20.113732545399444,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 1102.0,
   "end_distance_m": 1127.0,
   "start_elevation_m": 292.11513802610045,
   "end_elevation_m": 297.1435711624503,
   "min_gradient_pct": -1.5069360096139235
  },
  {
   "window_m": 50.0,
   "max_gradient_pct": 19.296704683912594,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 1077.0,
   "end_distance_m": 1127.0,
   "start_elevation_m": 287.495218820494,
   "end_elevation_m": 297.1435711624503,
   "min_gradient_pct": -0.7335105313756571
  },
  {
   "window_m": 100.0,
   "max_gradient_pct": 18.681748229435357,
   "diagnostic": false,
   "flags": [],
   "start_distance_m": 1033.0,
   "end_distance_m": 1133.0,
   "start_elevation_m": 279.514788573142,
   "end_elevation_m": 298.1965368025774,
   "min_gradient_pct": 0.1124458318553252
  }
 ],
 "shape": {
  "ascent_concentration": 0.386,
  "concentration_window_frac": 0.25,
  "longest_pitch_10pct_m": 328.0,
  "shape_class": "sustained"
 },
 "length_m": 1165.2126300616574,
 "start_elevation_m": 179.34298314712464,
 "end_elevation_m": 301.0185978744608,
 "endpoint_gain_m": 121.67561472733615,
 "overall_gradient_pct": 10.442352888064532,
 "accumulated_ascent_m": 122.18734246950208,
 "window_maxima": {
  "max_5m": {
   "gradient_pct": 20.852393190823477,
   "start_distance_m": 1122.0,
   "end_distance_m": 1127.0,
   "midpoint_distance_m": 1124.5,
   "start_elevation_m": 296.10095150290914,
   "end_elevation_m": 297.1435711624503,
   "start_xy": [
    643163.6631410365,
    4609784.410312054
   ],
   "end_xy": [
    643158.7954802596,
    4609783.296477724
   ]
  },
  "max_10m": {
   "gradient_pct": 20.58893756325233,
   "start_distance_m": 1117.0,
   "end_distance_m": 1127.0,
   "midpoint_distance_m": 1122.0,
   "start_elevation_m": 295.0846774061251,
   "end_elevation_m": 297.1435711624503,
   "start_xy": [
    643168.4710535036,
    4609785.780728595
   ],
   "end_xy": [
    643158.7954802596,
    4609783.296477724
   ]
  },
  "max_20m": {
   "gradient_pct": 20.158102300872827,
   "start_distance_m": 1107.0,
   "end_distance_m": 1127.0,
   "midpoint_distance_m": 1117.0,
   "start_elevation_m": 293.11195070227575,
   "end_elevation_m": 297.1435711624503,
   "start_xy": [
    643178.1325546684,
    4609788.360533868
   ],
   "end_xy": [
    643158.7954802596,
    4609783.296477724
   ]
  },
  "max_25m": {
   "gradient_pct": 20.113732545399444,
   "start_distance_m": 1102.0,
   "end_distance_m": 1127.0,
   "midpoint_distance_m": 1114.5,
   "start_elevation_m": 292.11513802610045,
   "end_elevation_m": 297.1435711624503,
   "start_xy": [
    643182.9633052507,
    4609789.650436504
   ],
   "end_xy": [
    643158.7954802596,
    4609783.296477724
   ]
  },
  "max_50m": {
   "gradient_pct": 19.296704683912594,
   "start_distance_m": 1077.0,
   "end_distance_m": 1127.0,
   "midpoint_distance_m": 1102.0,
   "start_elevation_m": 287.495218820494,
   "end_elevation_m": 297.1435711624503,
   "start_xy": [
    643207.1170581626,
    4609796.099949685
   ],
   "end_xy": [
    643158.7954802596,
    4609783.296477724
   ]
  },
  "max_100m": {
   "gradient_pct": 18.681748229435357,
   "start_distance_m": 1033.0,
   "end_distance_m": 1133.0,
   "midpoint_distance_m": 1083.0,
   "start_elevation_m": 279.514788573142,
   "end_elevation_m": 298.1965368025774,
   "start_xy": [
    643249.6638831393,
    4609807.313690443
   ],
   "end_xy": [
    643152.8208103076,
    4609783.3915256765
   ]
  }
 },
 "window_minima": {
  "min_5m": {
   "gradient_pct": -2.176579559380798,
   "start_distance_m": 715.0,
   "end_distance_m": 720.0,
   "midpoint_distance_m": 717.5,
   "start_elevation_m": 247.29149157189798,
   "end_elevation_m": 247.18266259392894,
   "start_xy": [
    643545.8198813846,
    4609852.576976628
   ],
   "end_xy": [
    643542.5044015275,
    4609856.319648577
   ]
  },
  "min_10m": {
   "gradient_pct": -1.942210695131621,
   "start_distance_m": 715.0,
   "end_distance_m": 725.0,
   "midpoint_distance_m": 720.0,
   "start_elevation_m": 247.29149157189798,
   "end_elevation_m": 247.09727050238482,
   "start_xy": [
    643545.8198813846,
    4609852.576976628
   ],
   "end_xy": [
    643539.1218605324,
    4609859.998387588
   ]
  },
  "min_20m": {
   "gradient_pct": -1.727324227390028,
   "start_distance_m": 713.0,
   "end_distance_m": 733.0,
   "midpoint_distance_m": 723.0,
   "start_elevation_m": 247.3230136808768,
   "end_elevation_m": 246.9775488353988,
   "start_xy": [
    643547.1460733275,
    4609851.0799078485
   ],
   "end_xy": [
    643533.3936277699,
    4609865.582951082
   ]
  },
  "min_25m": {
   "gradient_pct": -1.5069360096139235,
   "start_distance_m": 712.0,
   "end_distance_m": 737.0,
   "midpoint_distance_m": 724.5,
   "start_elevation_m": 247.33462971030437,
   "end_elevation_m": 246.9578957079009,
   "start_xy": [
    643547.809169299,
    4609850.331373459
   ],
   "end_xy": [
    643530.5419819899,
    4609868.387834046
   ]
  },
  "min_50m": {
   "gradient_pct": -0.7335105313756571,
   "start_distance_m": 707.0,
   "end_distance_m": 757.0,
   "midpoint_distance_m": 732.0,
   "start_elevation_m": 247.32752448029277,
   "end_elevation_m": 246.96076921460494,
   "start_xy": [
    643551.1246491562,
    4609846.58870151
   ],
   "end_xy": [
    643512.6345368875,
    4609876.00420054
   ]
  },
  "min_100m": {
   "gradient_pct": 0.1124458318553252,
   "start_distance_m": 676.0,
   "end_distance_m": 776.0,
   "midpoint_distance_m": 726.0,
   "start_elevation_m": 247.15568291632056,
   "end_elevation_m": 247.26812874817588,
   "start_xy": [
    643571.680624271,
    4609823.384135427
   ],
   "end_xy": [
    643493.7626495288,
    4609878.181148904
   ]
  }
 },
 "diagnostic_window_maxima": {
  "max_2m": {
   "gradient_pct": 21.807961873804516,
   "start_distance_m": 40.0,
   "end_distance_m": 42.0,
   "midpoint_distance_m": 41.0,
   "start_elevation_m": 182.1193038452006,
   "end_elevation_m": 182.55546308267668,
   "start_xy": [
    643994.7295520897,
    4609834.123566348
   ],
   "end_xy": [
    643993.4581759742,
    4609832.579674263
   ]
  },
  "max_3m": {
   "gradient_pct": 22.57287659017398,
   "start_distance_m": 40.0,
   "end_distance_m": 43.0,
   "midpoint_distance_m": 41.5,
   "start_elevation_m": 182.1193038452006,
   "end_elevation_m": 182.7964901429058,
   "start_xy": [
    643994.7295520897,
    4609834.123566348
   ],
   "end_xy": [
    643992.8224879166,
    4609831.807728219
   ]
  }
 },
 "diagnostic_note": "Windows <=3 m are at raster-noise scale (1-sigma raster noise alone is roughly +/-7 pp at 2 m and +/-5 pp at 3 m on a 1 m DTM). Diagnostic use only: never a headline or ranking value.",
 "quality_summary": {
  "review": [],
  "extent": [
   "may_continue_beyond_end"
  ]
 },
 "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/ct/USGS_1M_18_x64y461_CT_Statewide_C16.tif"
  ],
  "calculated_at": "2026-08-24T21:56:44+00:00",
  "road_source": "OpenStreetMap (local PBF extract)",
  "road_attribution": "\u00a9 OpenStreetMap contributors, ODbL",
  "osm_pbf_path": "data/cache/pbf/connecticut-2026-08-23.osm.pbf",
  "osm_snapshot": "2026-08-22T20:21:28Z",
  "run_id": "redo-ct-1-260824",
  "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, CT_Statewide_C16 (collected 2016)",
  "elevation_tile_ids": [
   "x64y461"
  ],
  "climb_origin": "discovered",
  "notes": "Coarse pass: max 12.8% over 200 m (Terrain 50), gain 68.1 m over 798 m way. EXTENDED by graph walk: +0 segment(s) at base, +3 at top (stop: base=no_descending_continuation, top=no_ascending_continuation; min_avg=2.0%). Review before adopting. DEDUPE: absorbed 1 overlapping proposal(s): calhoun-hill-road ADOPTED (NE wave 1, 2026-08-25): clean-steep. Wales dials per PRODUCTION 'US ADOPTION DIALS'.",
  "canopy_check": "unavailable \u2014 no surface model (DSM or point cloud) registered for this coverage",
  "license": "ODbL-1.0",
  "license_url": "https://howsteep.org/licensing.html"
 },
 "area": {
  "place": "Washington",
  "county": "Connecticut"
 }
}