Sources
Where this comes from
Everything in this guide is drawn from public sources, by a program you can read. This page lists the sources, says how the maps were made, and is honest about what is not known.
The data
| What | Source | Notes |
|---|---|---|
| Elevation | Medium Resolution Digital Elevation Model (MRDEM-30), Natural Resources Canada | 30 m bare earth model. Read directly from the national cloud optimized file. Open Government Licence, Canada. The 1 to 2 m lidar model does not cover the ridge. |
| Ground cover | 2020 Land Cover of Canada, Natural Resources Canada | 30 m classes from Landsat. Open Government Licence, Canada. |
| Snow onset | Annual 30 m snow dynamics, 2018 to 2025, Natural Resources Canada | First and longest snow periods for seven winters. Open Government Licence, Canada. |
| Satellite imagery | Copernicus Sentinel-2 level 2A, 2026-09-18, through Element 84 Earth Search | Contains modified Copernicus Sentinel data 2026. Scenes: S2A_11ULV_20260918_1_L2A, S2A_11ULA_20260918_1_L2A. |
| Wildlife management units, parks, wildlife ranges, coal agreements | Government of Alberta geospatial services | Open Government Licence, Alberta. |
| Roads, trails, rivers, summits, services | OpenStreetMap contributors | Open Database Licence. Mapped by volunteers; may be missing or out of date. |
| Place names | Canadian Geographical Names Database | Open Government Licence, Canada. |
| Weather history and forecast | Open-Meteo | ERA5 reanalysis and global forecast models. Creative Commons Attribution 4.0. |
| Magnetic declination | World Magnetic Model 2025, NOAA and the British Geological Survey | Public domain. Computed by this guide's program and checked against the published test values. |
| Regulations | 2026 Alberta Guide to Hunting Regulations; Wildlife Regulation, Alta Reg 143/97 | Read on 28 September 2026. |
| Goat study and ridge ecology | Côté (2010), Wild Lands Advocate; published papers of the Caw Ridge study; Alberta Wilderness Association, Kakwa | |
| Access directions | Municipal District of Greenview | Road reports from public forum threads, 2008 to 2023, marked as such where used. |
| Bear safety | Government of Alberta, Bears and hunters | |
| Map lettering and site type | Barlow by Jeremy Tribby, PT Serif by ParaType, IBM Plex Mono by IBM | SIL Open Font Licence. |
| Interactive map | Leaflet | BSD 2-Clause licence. |
| 3D view | three.js | MIT licence. |
How the maps are made
One program, cawridge, written in Rust, does all of it. It has two commands. cawridge fetch downloads the data; cawridge build draws the maps and writes the site.
- Reading the elevation. The national elevation model is a single file of several hundred gigabytes. It is stored so that any window can be read without the rest: the program asks the server for the index, then for only the 36 tiles that cover the region. It takes about three seconds. The projection from latitude and longitude to the file's Lambert grid is worked out in the program and tested against the PROJ library.
- Relief. Slope and aspect by Horn's method; shading from four lights so that slopes facing away from the main light keep their form.
- Contours. Marching squares on a bicubic resampling of the model, joined into lines and thinned.
- Streams. Pits in the model are filled, each cell passes its water to its lowest neighbour, and cells with enough ground above them become streams. Big rivers come from OpenStreetMap instead.
- Sight lines. For each target cell the ground between it and the eye is checked against the straight line between them, allowing for the curve of the earth and the bending of light. Eye at 1.7 m, target at 1.0 m.
- Sun. The sun's position every ten minutes from the NOAA solar equations; a ray marched from each cell towards it until it clears the highest ground or strikes a slope.
- Walking time. Dijkstra's algorithm over the grid with Tobler's hiking function as the cost.
- Summits and saddles. The grid is flooded from the highest cell down, joining cells into islands. Where two islands meet is a saddle, and the lower island's top is a summit whose prominence is its height above that meeting point.
- Landforms. The topographic position index of Weiss at 300 m and 2 km, each scaled by its own spread, with slope, gives ten classes.
- Wind shelter. Winstral's upwind slope: the steepest angle to the ground within 300 m, looking into the prevailing wind of the weather record across a 30 degree fan.
- The 3D view raises a mesh from the same elevation grid in your browser with the three.js library and drapes the maps over it. What you see standing on a point is drawn from 30 m data and bare ground.
- Lettering and line work are composed as SVG and rasterised by the resvg library, so the maps need no browser and no mapping software to build.
What is not known
The research for this guide could not settle the following. Treat each as an open question and ask locally.
- Whether the conservation area named in the Upper Smoky Sub-regional Plan has been legally created, and where off-highway vehicles will be allowed within it.
- The present state of gates, signs and bridges on Beaverdam Road and Sheep Creek Road, and any check-in or firearm rule the mine applies to traffic through its property.
- Whether a radio is required on Beaverdam Road, and on which channel.
- Whether the goat study is active this season, and the present size of the herd.
- Phone coverage on the ridge, and water on the crest.
- The wolf season end date for 446: the guide gives 31 May, or 15 June in units where the bear season runs to 15 June, and 446 fits neither case cleanly.
- The origin of the name. "Caw Ridge" is not an official name: the Canadian names database knows only Caw Creek, and older writing calls the ridge Copton Ridge, a name the database now places about 11 km to the north.
- Two published numbers exist for the hospital. This guide gives the one on the facility's own page. In an emergency call 911.
Limits of the maps
- The elevation model's cell is 30 m. Features smaller than that are smoothed away. Slope reads low on short cliffs. The 10 m contours of the close sheet are interpolated.
- Sight lines are over bare ground. Trees, krummholz and boulders hide more than the maps show.
- Ground cover is a 2020 satellite classification. Cutblocks, burns and mine work since then do not appear; the satellite image of September 2026 does show them.
- Boundaries are drawn from official files but the legal boundary is the written description.
- Positions are on NAD83, which agrees with the WGS84 of a GPS to within about a metre and a half here.
Built 29 Sep 2026, 17:27 MDT.