Mappers in or of North America, join us on March 4 for a #mappyhour hosted by @OpenStreetMapUS. RSVP today: https://openstreetmap.us/events/mappy-hours/2026/03/ohm-north-america/

A proof of concept for OpenHistoricalMap Americana simulates a road atlas at any point in the history of highway construction. Tour down #route66 and the other highways that existed at the time. https://openstreetmap.us/events/mapping-usa/2026/history-hits-the-road/ […]

Help us make 2026 an historic year by participating in our first-ever donation drive! Your generous donation will go directly toward making #openhistoricalmap easier to use and contribute to and ensure that our services remain available and reliable as demand increases. Find out more about the […]

All OpenHistoricalMap websites and APIs will be down for approximately 30 minutes this Thursday from 15:00 UTC for a planned server configuration change to improve site reliability. We apologize for the inconvenience.

In January, the #openhistoricalmap community added 65,731 dated elements, 9,668 buildings, and 15,303½ railroad miles. The average age of a dated element rose by more than 7 years, and the average year shifted more than 4 years earlier. All this with the help of 39 new contributors – welcome! […]

RE: https://en.osm.town/@osm_tech/115968544599864782 This 😣

In December, the #openhistoricalmap community added 55,351 dated elements, 13,877 buildings, and 8,959 railroad miles. The average age of a dated element fell by 8 months, and the average year shifted one year later. All this with the help of 31 new contributors – welcome! […]

The biggest things that happened in #openhistoricalmap development over the past 6 months 🧵 https://forum.openhistoricalmap.org/t/staying-afloat-wikimedia-logins-ancient-writing-and-more/642

In November, the #openhistoricalmap community added 62,421 dated elements, 21,441 buildings, and 8,072½ railroad miles. The average age of a dated element fell by 17 months, and the average year shifted one year later. All this with the help of 40 new contributors – welcome! […]

RE: https://mapstodon.space/@mapsmania/115617207189840155 A gorgeous new way to explore OpenHistoricalMap’s coverage of #historicboundaries

What sorts of things do georeferenced maps make possible? This interface turns a street address into a point, finds georeferenced maps from the SLV that include that point, then displays the historic maps with a marker showing the location of the modern address. #slvresidency

The OpenHistoricalMap database will be in read-only mode for a planned upgrade next Monday, November 24, at 19:00 UTC. We expect the upgrade to take approximately 3 hours. During that time, you won’t be able to save any changes, but you’ll be able to view and query the map as usual. Thank you […]

There's a new version of the AllMaps editor out, which means I'll need to update my SLV georeferencing documentation! It works the same, but some things have been moved or added. Now includes a 'search' option in the georefencing panel that should make it easier to match maps.

It was a privilege to introduce the software #internationalization and #localization community to #openhistoricalmap (and #OpenStreetMap and @maplibre) at #utw2025. Join us in mapping yesterday already! #i18n #l10n

In October, the #openhistoricalmap community added 87,784 dated elements, 28,666 buildings, and 15,202½ railroad miles. The average age of a dated element fell by 15 months, and the average year shifted one year later. All this with the help of 40 new contributors – welcome! […]

Anyone mapping the history of the German Autobahn? We have a particularly fleißig mapper who's coordinating the daunting task of mapping the historical evolution of die Bundesautobahn. He's off to a great start... and he'd love to have helpers. Maybe, just […] [Original post on mapstodon.space]

New prototype from my #SLVResidency! This one lets you explore photos from the Committee for Urban Action collection by selecting one of the highlighted roads on a map of Victoria. It's very much work-in-progress and will probably change a lot, but you can […] [Original post on hcommons.social]

We’re aware that the map on our homepage is currently nonfunctional in some languages. If you are seeing this issue, please switch the interface to English for now. Thank you for your patience. https://forum.openhistoricalmap.org/t/broken-homepage-map-in-some-languages-and-inspector-images/580

Had a great time presenting about how OHM & #wikimedia can be used together at @WikiConferenceNA. The focus of our talk was on how OHM data's tagging can include to add source information not just for geometry, but also for attributes, and that all of this is easily downloadable for reuse […]

If you’re in #loouhvull for #nacis #nacis2025, look out for these OpenHistoricalMap stickers. Snag one and keep it real! (For the record, we have a scale bar too.) #realmapshavetimesliders

We've set up some new networking rules on our sites, so if you're seeing any 503 or other errors, please DM and we'll fix things up! #notyoubots

In the past five weeks, the #openhistoricalmap community added 78,430 dated elements, 10,580 buildings, and 20,439¼ railroad miles. The average age of a dated element fell by 21 months, and the average year shifted 17 months later. All this with the help of 30 new contributors – welcome! […]

Mabuhay @sotm! If you’re in Manila for #sotm #sotm2025, come find @mxn for some troublemaker’s stickers!

¡Muchísimas gracias a @osmlatam por la oportunidad de introducir #openhistoricalmap a los mapeadores latinoamericanos con la charla por @rub21 y @mxn en #sotmlatam #sotmlatam2025 el sábado pasado! ¡Agradecemos el entusiasmo de todos y esperamos contar la geohistoria juntos! […]

¡Buenas días de #Medellín y #sotmlatam #sotmlatam2025! ¡Agradecemos a encontrar todos los mapeadores aquí! @rub21 y @mxn van a presentar sobre la tema de #openhistoricalmap el sábado.

In the past month, the #openhistoricalmap community added 71,946 dated elements, 12,256 buildings, and 10,475¾ railroad miles. The average age of a dated element fell by 13 months, and the average year shifted 4 months later. All this with the help of 30 new contributors – welcome! […]

Clues about history are never far if you know what to look for. Neither is @vespucci_editor. With its new support for editing OpenHistoricalMap, you can jot down what you learn from a #cornerstone #plaque #sidewalkstamp or the impressions left by #abandonedrailways right on the spot while on a […]

Ian Spangler gives an overview of the map resources at @bplmaps and tools for turning them into geodata: https://openstreetmap.us/events/state-of-the-map-us/2025/urban-atlases-library-collections-and-historical-geodata/ #stateofthemapus #sotmus

The South Bay is looking a little busier in #OpenHistoricalMap. @impiaaa imported comprehensive historical coverage of #TrafficLights from #SanJose #DOT. Now you can tell when major streets were built based on when the traffic lights came on […] [Original post on sfba.social]

Whether you go big or go small, you can’t map it all. But you can lay a foundation to grow and guide a new historical mapping community. @mxn mixes as many metaphors as possible to show us how: https://www.youtube.com/watch?v=5h3y5GnkJEY #stateofthemapus #sotmus

We’re aware of a performance issue affecting history pages since we deployed a new version of the website last week. Our developers have identified the cause and are working on a fix. Thank you for your patience. https://github.com/OpenHistoricalMap/issues/issues/1111

In the past month, the #openhistoricalmap community added 55,883 dated elements, 13,636 buildings, and 19,387¼ railroad miles. The average age of a dated element fell by 13 months, and the average year shifted 5 months later. All this with the help of 29 new contributors – welcome! […]

For the last few years, we’ve been proud to be the first Open*st*r*Map project to display a #vectortiles map right on the homepage. But now we aren’t alone anymore, and that’s a much better feeling! Congratulations on this milestone, big sibling! https://en.osm.town/@osm_tech/114898903969607933

OpenHistoricalMap is about both big and small. Case in point: @jeffme can’t talk about #empire without talking about 💩 https://www.youtube.com/watch?v=rkiUYDZ5yLo #stateofthemapus

Our friends at @developmentseed are always working on clever tooling that makes it possible to sustain an ambitious community-driven project like ours. Watch Hanbyul Jo’s rundown at #stateofthemapus: https://www.youtube.com/watch?v=3xdm3I_5v10

Working with religious boundaries that change over time? OHM might be the place for you. You can store, collaborate, and see boundaries in their historical context. Here's an animation of the history of the Catholic Diocese of Cincinnati […]

In the past month, the #openhistoricalmap community added 55,401 dated elements, 23,116 buildings, and 15,467 railroad miles. The average age of a dated element fell by 19 months, and the average year shifted 18 months later. All this with the help of 35 new contributors – welcome! […]

Just in time for #stateofthemapus next week, we landed some long-awaited features on top of the many other things we quietly released on #openhistoricalmap over the past few months. Check out the details on the forum […]

In the past month, the #openhistoricalmap community added 49,939 dated elements, 5,965 buildings, and 293,247¼ railroad miles. The average age of a dated element fell by 14 months, and the average year shifted over 6 months later. All this with the help of 31 new contributors – welcome! […]

In the past month, the #openhistoricalmap community added 50,639 dated elements, 5,919 buildings, and 3,996¼ railroad miles. The average age of a dated element fell by 15 months, and the average year shifted 9 months later. All this with the help of 25 new contributors – welcome! […]

The more modern branch of #openrailwaymap has started double-tracking #OpenStreetMap and #openhistoricalmap data. Finally – appreciate #abandonedrailways in the proper setting! https://forum.openhistoricalmap.org/t/openrailwaymap-adds-openhistoricalmap/446 https://openrailwaymap.fly.dev/ […]

The official #openhistoricalmap account on #bluesky is now https://bsky.app/profile/openhistoricalmap.org/ (renamed from ohmap.bsky.social). We created the new account because ohm.mapstodon.space.ap.brid.gy was read-only – we couldn’t repost or reply to anyone using #bridgyfed. But we’ll keep […]

@aoppo whipped up a user script to easily navigate #OpenHistoricalMap while reading a #Wikipedia article. You can install it in your personal Wikipedia account: https://globstory.it/wikipedia-user-script/ It’s one of many ideas for cooperation between the […] [Original post on mapstodon.space]

Why is everyone pulling their #aprilfools pranks so soon? It’s only the 19th day of March. What did we miss? #oldstyle #juliancalendar

In the past month, the #openhistoricalmap community added 49,375 dated elements, 5,757 buildings, and 2,615 railroad miles. The average age of a dated element fell by almost two years, and the average year shifted one year later. All this with the help of 18 new contributors – welcome! […]

OpenHistoricalMap and open source software let you tell stories in the proper historical context: https://mastodon.social/@CharliePlett/114247969119307235 Learn how to incorporate OHM into your own project: https://wiki.openstreetmap.org/wiki/OpenHistoricalMap/Reuse #dataviz

Start and end #dates are very important for a #historicalgis project. We managed to stuff dates into more of the website’s nooks and crannies, so you always know which stage of a boundary or building’s evolution you’re looking at, or whether it’s even the one you’re looking for. #hgis

Our #OSMCha instance makes it easy to inspect large changesets for subtle changes. Sometimes, those changes look very wrong, but only because modern aerial imagery doesn’t line up with the historical features being mapped. Now you can visualize changesets […] [Original post on mapstodon.space]

@beniamin mapped the hotels in #Berlin as of 1910 and used #qgis to visualize their geographical distribution within the city: https://forum.openhistoricalmap.org/t/mapped-former-hotels-in-berlin/427