diff --git a/Rakefile b/Rakefile
index f585fa4..f7891b1 100644
--- a/Rakefile
+++ b/Rakefile
@@ -23,3 +23,33 @@ namespace :overpass do
     puts "Wrote #{geojson["features"].size} POIs to #{args[:out]}"
   end
 end
+
+namespace :gpx do
+  desc "Backfill properties.id on Note-category features saved before edit/delete (and its id targeting) existed"
+  task :backfill_note_ids do
+    require "json"
+    require "securerandom"
+
+    data_dir = ENV.fetch("MAPTOOL_DATA_DIR") { File.join(__dir__, "data") }
+    count = 0
+    Dir.glob(File.join(data_dir, "gpx", "**", "*.geojson")).each do |file|
+      # ".gpx.geojson"/".fit.geojson" are GpxStore's own cache sidecars for
+      # an uploaded GPX/FIT (regenerated from the source on demand, see
+      # GpxStore#geojson) — never hand-drawn notes, not worth touching.
+      next if file.end_with?(".gpx.geojson", ".fit.geojson")
+
+      collection = JSON.parse(File.read(file))
+      changed = false
+      (collection["features"] || []).each do |feature|
+        properties = (feature["properties"] ||= {})
+        next unless properties["category"] == "Note" && !properties["id"]
+
+        properties["id"] = SecureRandom.uuid
+        changed = true
+        count += 1
+      end
+      File.write(file, JSON.generate(collection)) if changed
+    end
+    puts "Backfilled #{count} note id(s)"
+  end
+end
diff --git a/TODO.adoc b/TODO.adoc
index 960827a..5824c1d 100644
--- a/TODO.adoc
+++ b/TODO.adoc
@@ -44,6 +44,7 @@ independence from connectivity.
 ** [x] Save a distance/area shape as a note too — Measure already draws these by hand, so a "Save" button there (not a second click-to-draw UI in the notes tool) reuses that instead of duplicating it; both share one `NoteSaveForm` (notes.js). `gpx.js`'s `_addLayers` now renders Polygon and note-flagged LineString features (fill/outline, dashed line), not just points
 ** [x] Edit/delete individual notes from their popup (logged-in only) — targets a feature by a client-generated `properties.id` (`GpxStore#update_feature`/`#delete_feature`), not array position
 ** [x] Measure's vertices are draggable (mousedown + move, `event.preventDefault()` to stop the map's own drag-pan) and deletable (click to select — shown in yellow — then Delete/Backspace)
+** [x] Fixed: a note saved before `properties.id` existed (the earliest test notes) had no Edit/Delete-able target — the popup no longer offers them without an id, and `rake gpx:backfill_note_ids` assigns one to any pre-existing Note feature missing it
 ** [x] Gated behind login: NotesControl isn't added to the map at all when logged out, Measure's "Save as note" button is hidden (Measure itself stays usable either way)
 ** [ ] The Unigrid Matrix category filter only re-slices the *points* source (`_applyCategoryFilter`) — toggling the "Note" category off hides point notes but not polygon/line ones sharing that category
 * [ ] Offline satellite tile caching (e.g. ESRI) for a selected route area — key for judging surface quality and obstacles when wild camping
diff --git a/public/js/gpx.js b/public/js/gpx.js
index 766c66a..2b19e8d 100644
--- a/public/js/gpx.js
+++ b/public/js/gpx.js
@@ -696,7 +696,10 @@ export class GpxPanelControl {
     this._map.on("click", layerId, (event) => {
       const feature = event.features[0];
       if (!feature) return;
-      const editable = feature.properties.category === "Note" && isLoggedIn();
+      // properties.id is what update/delete target by — a note saved before
+      // that existed (see `rake gpx:backfill_note_ids`) doesn't have one
+      // yet, and offering Edit/Delete for it would just 404.
+      const editable = feature.properties.category === "Note" && !!feature.properties.id && isLoggedIn();
       const popup = new Popup({ closeButton: true, maxWidth: "260px" })
         .setLngLat(event.lngLat)
         .setHTML(popupHtml(feature.properties, { editable }))