Rowan County Explorer

Over the years teaching GIS & mapping, Boyd has tried to connect his students with real-world mapping opportunities. One such opportunity emerged when Rowan County, Kentucky, wanted an interactive map showing trails and tourism destinations in the area. Workshopping with students in GEO 305 (Elements of Cartography) and later MAP 672 (Programming for Web Mapping) in UKy’s Department of Geography, he drafted a web map.

Rowan County, Kentucky, trail and tourism explorer
Trail and tourism explorer for Rowan County, Kentucky:

The criteria for this map were that it needed to be completely open source (without relying on any for-fee platforms) and self-contained—the project lives in a folder that could be dropped into any web server and would just work. This project uses LeafletJS and public base maps from Kentucky DGI.

The page departs from the traditional web map; marginalia, typically on a print map, was added to this map. A viewer can zoom into the legend! While the creative choices made on this project offered a fulfilling experience, students have their own trajectories and soon pivot interests after a course is finished.

The project is a draft, but it is active. Tell us what you think:

New base maps for Sheltowee Trace

Find high-resolution aerial imagery and shaded relief maps for Kentucky (and some for Tennessee) on

Base maps for
Base maps for

We’re adding new base maps for our Sheltowee Trace map. The current maps are:

  • Default map shows a generalized shaded relief, hydrologic features, and public land.
  • Aerial photography shows 2-ft pixel resolution, leaf-off 2019 imagery.
  • Shaded relief (KY) uses KyFromAbove point clouds from 2010s to create a shaded relief detailed enough to show trail and road beds.
  • Topographic (KY) shows the Topographic map series created by the Kentucky Division of Geographic Information.
  • Topographic (Maptiler) displays a modifed Maptiler Outdoors base map. It is a global base map pulled a variety of open-source data. Trail and other information portrayed on this base map is not maintained by outrageGIS mapping. Also, elevation contours can show errors around 100 feet.

Cumulative elevation gain calculator

How much elevation gain did you have on your last Sheltowee Trace hike? We built a calculator and elevation profile on

Cumulative elevation gain calculator on
Cumulative elevation gain calculator on

The data used in the calculator is pulled from lidar point cloud elevations created in the mid-2010s. Digital elevation models (DEM) derived from these point clouds have a 5-ft spatial resolution and are detailed enough to show wider trails in shaded relief rendering of the DEM. The point elevations for the Sheltowee Trace are sampled every 1/10th of a mile and allow for calculating gains between mile markers with a single decimal place. The result shows both southbound and northbound gains.

Terrain Explorer

In this web map, we explore how to use different elevation models in 3D maps. The KyFromAbove project collects and maintains high-resolution elevation data and aerial imagery for Kentucky. The bare-earth Digital Elevation Model (DEM) was created from a lidar point cloud. This is the typical elevation model that we use. The same point cloud was then filtered to create a Digital Surface Model (DSM) showing above-ground elevations, like buildings and trees. Both of these elevation models were converted to terrain tiles to use in web mapping applications. MapLibre GL JS 3D features terrain rendering with RGB-encoded elevation raster tiles.

Terrain Explorer
Explore different terrain models at

The sliders allow the viewer to change the vertical exaggeration of the DEM and DSM. If geolocation is enabled, a track will record the viewer’s location. That track can be downloaded as a GeoJSON (works in Chrome).

Visit the page:

This was a project in the UKy Geography MAP 675, a course in the department’s Digital Mapping MS graduate program. The aerial imagery and elevation data are from 2019.


We love hiking the Sheltowee Trace. Often, we want to know how much vertical elevation gain we have accumulated over a longer hike. To this end, we’ve added a cumulative elevation gain calculator to Give it a try and tell us what you think.

Sheltowee Trace web page and map

Canopy height model

An analysis estimating tree canopy heights using KyFromAbove lidar point clouds (2019) combined with an NDVI layer derived from NAIP 2018 imagery for Lexington, Kentucky 2019. 19.3% in canopy cover.

Interactive map for existing canopy and for trees removed between 2010 and 2019.

Because of the difference between the lidar and photographic sensors, artifacts are present around tall structures like water towers, powerlines, and buildings.

Tree canopy model

GEO 409, Spring 2024.

Campus change, 2010-2019

Winner: Best Spatial Analysis at the 2023 Kentucky Association of Mapping Professionals annual conference.

This analysis shows the difference between two digital surface models (DSM) created from lidar point cloud data hosted by DSMs allow us to visualize surface features like buildings and trees. The calculation subtracts the 2010 DSM from the 2019 DSM to find the height difference. The resulting raster layer is multiplied over a shaded relief base map from the 2019 DSM.

Campus change, 2010-2019

The most prominent change is the addition of numerous dormitories, but the more minor changes are the extensive growth and removal of trees. The greatest increase in height (156 feet) occurred at the Commonwealth Stadium expansion and renovation in 2015. The most significant decrease in height (90 feet) occurred after removing a construction crane at the Albert B. Chandler Hospital.

View map and other visualizations of change:

@boydx Department of Geography at the University of Kentucky. GEO 409 Spring 2023.

RRG 3D terrain map

Interactive web maps have come a long way over the years. First we had slippy maps using raster tilesets – they’ve been around for about twenty years and are incredibly durable. However, once the tileset is rendered, it’s not easy to change the look of the raster image. You will need to render a new tileset and replace the old. Because a tileset can contain millions of images, it’s not a quick replacement.

Gaming technology evolved in the browser and brought us WebGL and vector tilesets. These tileset features have attributes and are rendered programatically in the browser. It’s rather easy to change the appearance of a feature and Mapbox built a browser application, Studio, to create endless styles of maps using vector features. What’s not easy is serving a vector tileset to a client until recently. Libraries like PMTiles bundle a vector tileset into a single file that expose the necessary to the client browser.

More recently, elevation (terrain) tilesets have made 3D maps more exciting to create and explore. Once an elevation is loaded, all other layers, tilesets, etc. are draped over elevation surface. Depending on the resolution of the elevation data, this surface can dramatically change the appearance of the map.

Using an open source mapping library like MapLibre GL JS, a browser can simultaneous consume raster, vector, and terrain tilesets to make a 3D map for any place you have data. Kentucky has excellent data availabilty including lidar data to make high-resolution elevation surfaces. This map uses that lidar data to create the terrain tileset and a shaded relief raster tileset. The vector tilesets for trails, roads, etc. are derived exclusively from OpenStreetMap. The water layers are from the USGS National Hydrological Dataset.

Below is a screen capture of the web page and a link. You might notice that it doesn’t have all of the trails that our printed maps show. We may add those trails in the future, because it would helpful for planning your trip. And, we’re not planning to move to an exclusive mobile app. With all of the advances in mobile technology, we think paper maps are still essential for learning basic navigation and map reading.

Screen Capture of map

The map can be loaded here:

Happy adventures!

GEO 509: Report Fall 2022

An analysis of flood-prone infrastructure and conditions in selected Eastern Kentucky watersheds.

In July 2022, eastern Kentucky experienced historic and devastating flash flooding caused by 14–16 inches of rainfall in a 5-day period. The National Weather Service gave a 1 in 1000 chance of this much rain falling during this period.

View maps and report:

Department of Geography, University of Kentucky, College of Arts and Sciences
December, 2022

A simple GPS tool for the phone

If you visit this site often, you likely have a favorite map app on your phone. I certainly do and I have installed dozens of apps over the years. Most focus on placing your location as a dot on the map.

The dot

Any map app that shows your location as a dot on the map fosters a dependence on your exact location. We end up saying, "I am here" instead of asking "Where am I?"

To build strong spatial awareness, we should look at the dot after studying the plain map and doing an exercise in terrain association. Can we orient the map (best done with a paper map, folks) so that map north aligns with observed north? Can we then identify features on the map and estimate their distance from us?

These are questions in topograhic map reading. If you carefully observe your environment and compare its representation on the map, you will not need the dot.

When there was no dot

Let’s say the early 1990s. Before that time, we used paper maps. Soon after, handheld GPS units became popular and only showed coordinates for your position and maybe some other location statistics like speed, elevation, distance & bearing to next waypoint. They were often used with a paper map that had a grid (with linear units on a flat space) or a graticule (angular units on a curved space) that helped a user measure their location.

Using coordinates, we looked at the paper map’s margin for marks that pointed you to a general location. To find the exact location, we looked up and asked, "Where am I?" and compared the map with what we saw. We built a mental map of our surroundings. There was no dot.

An app without a dot?

So, we thought we would kick it back to the 90s and make a browser app that mimics these early devices. Because our maps have detailed graticules and mile markers for the Sheltowee Trace, this app should compliment your journey into topography and map reading. This app is designed for mobile devices and below is a screen capture of a use on an iPhone.

Screen Capture of control panel

GPS app can be loaded here:

This app is free, open source, doesn’t need to be installed, and won’t collect any information from you.

Happy adventures!

Bluegrass Trails

Looking for a place to hike in the central Bluegrass? Check out this old-school style interactive map:

Bluegrass Trails interactive map
Bluegrass Trails interactive map

Experimenting with Geolocation API

We have a lot of great raster base map services available in Kentucky and I wanted to access them for my current location when I use my mobile device in the field. While there are many ways to make a mobile map, I wanted use Leaflet JS and build a custom geolocation service using the Geolocation API. Some desired features for the web page:

  • The interface should be just the map, with a single button to access the controls
  • Location services should record a track of previous locations with distance covered
  • Location coordinates should be averaged over a sample period to help with accuracy
  • Other information for the current location should be offered on the page, e.g., hourly weather forecasts.

Map cound found here:

The below screen capture shows the control panel for selecting base map and enabling the the location services. It also gratuitously adds content from the last three posts to this forum. (Practicing with Tailwind CSS for potential site redesign.)

Screen Capture of control panel

Please feel to add your comments and tell how it works on your mobile device. It has tested on Chrome and Safari mobile browsers.

Some caveats.

  • The tracking feature is tuned to walking. If you drive or bike, the track will more generalized the faster you travel.
  • Of course, you’ll need to enable location for the page :). I promise that nothing is used or saved from your session. This is a completely client-side app.
  • If you refresh your browser, the page is reset and your track is lost. Working on a local database option to save the track.
  • This page requires an online connection. Working on an offline version, too.

Screen Capture of control panel Above is an screen capture of the Kentucky Topo map for the state. Other base maps include, lidar-derived surface models and current GOES-16 imagery.

Screen capture of mobile device Screen capture of track mapping on a mobile device

Weather archive updates

We collect imagery from national park webcams in the Great Smokies and Mammoth Cave parks and then make animated gifs of those webcam images. In 2011, I penciled this quick note:

110629 Nice time-lapse photography for all cameras and satellite. Make movie?

Beginning in 2012, we started archiving these animations.

New webcam added to animation archive

Turns out, we had Mammoth Cave working for the entire 2021 year, but didn’t have them accessible via a web page. With a little grep and sed action, the gifs were added to the default page for the Great Smokies archive. Visit the interface here.

Weather and animation archive

We plan on having at least the last year covered in the archive. At 60 GB a year now with HD cameras, it can get expensive hosting multiple years. I do have the years back to 2012 stored offline.

New Red River Gorge map

Over the past spring, we’ve been revamping our popular map for the Red River Gorge. The map should be available in early June. One of the additions is a new Bird’s Eye View map that user lidar elevation data and Blender 3d modeling software. You can view a zoomable image with this link

New map in our printed series for the Red River Gorge
New map in our printed series for the Red River Gorge

2020 Census data

Time to explore the data on a map. The experiment is show block group data for select demographic data, which was used for redistricting. This interactive presentation is a test of concept to show population density. Eventually, an UI element will be added to symbolize block groups by precent population in self-identified racial group – as defined in Census categories.

Kentucky Population density, 2020 Census with selected racial demographics by Block Group

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