diff --git a/ohmg/api/schemas.py b/ohmg/api/schemas.py
index 428ba8a7..84d7083e 100644
--- a/ohmg/api/schemas.py
+++ b/ohmg/api/schemas.py
@@ -497,7 +497,7 @@ def resolve_id(obj):
 
     @staticmethod
     def resolve_layers(obj):
-        return natsorted(obj.layer_set.all(), key=lambda k: k.title)
+        return natsorted(obj.get_layers(), key=lambda k: k.title)
 
     @staticmethod
     def resolve_name(obj):
@@ -651,7 +651,9 @@ def resolve_loaded_by(obj):
     @staticmethod
     def resolve_locks(obj):
         locks = [
-            i for i in SessionLock.objects.all().prefetch_related() if i.target and i.target.map.pk == obj.pk
+            i
+            for i in SessionLock.objects.all().prefetch_related()
+            if i.target and i.target.map.pk == obj.pk
         ]
         return locks
 
diff --git a/ohmg/core/management/commands/oneoffs.py b/ohmg/core/management/commands/oneoffs.py
index db1a0cc4..93af59f4 100644
--- a/ohmg/core/management/commands/oneoffs.py
+++ b/ohmg/core/management/commands/oneoffs.py
@@ -26,6 +26,7 @@ def add_arguments(self, parser):
                 "fix-full-region-files",
                 "set-tilejson",
                 "delete-duplicate-regions",
+                "add-masks-to-layers",
             ],
             help="Choose what operation to run.",
         )
@@ -408,3 +409,24 @@ def old_ds_to_new(file_set):
                 if not dry_run:
                     delete_ps.delete()
                     print("deleted")
+
+        ## Mar 11th, 2026
+        elif operation == "add-masks-to-layers":
+            from django.contrib.gis.geos import GEOSGeometry
+
+            from ohmg.core.models import Layer, LayerSet
+
+            for ls in LayerSet.objects.all():
+                print(ls)
+                if ls.multimask:
+                    for k, v in ls.multimask.items():
+                        print(k)
+                        ## there SHOULD only be one layer here, but per ticket
+                        ## #308 some regions got duplicated, and some of the
+                        ## duplicates got georeferenced :(. Can't clean all of
+                        ## that up now, so... using filter here
+                        layers = Layer.objects.filter(slug=k, region__document__map=ls.map)
+                        for layer in layers:
+                            layer.mask = GEOSGeometry(json.dumps(v["geometry"]))
+                            layer.save(skip_map_lookup_update=True)
+                print("")
diff --git a/ohmg/core/migrations/0009_layer_mask.py b/ohmg/core/migrations/0009_layer_mask.py
new file mode 100644
index 00000000..420aa891
--- /dev/null
+++ b/ohmg/core/migrations/0009_layer_mask.py
@@ -0,0 +1,19 @@
+# Generated by Django 4.2.27 on 2026-03-11 17:19
+
+import django.contrib.gis.db.models.fields
+from django.db import migrations
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('core', '0008_auto_20250915_1937'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='layer',
+            name='mask',
+            field=django.contrib.gis.db.models.fields.PolygonField(blank=True, null=True, srid=4326),
+        ),
+    ]
diff --git a/ohmg/core/models.py b/ohmg/core/models.py
index be2e2325..a9b7e97d 100644
--- a/ohmg/core/models.py
+++ b/ohmg/core/models.py
@@ -4,7 +4,7 @@
 import urllib.parse
 from datetime import datetime
 from pathlib import Path
-from typing import Union
+from typing import Iterable, Union
 
 from django.conf import settings
 from django.contrib.auth import get_user_model
@@ -284,7 +284,7 @@ def stats(self):
 
         main_layerset = self.get_layerset("main-content")
         if main_layerset:
-            main_lyrs_ct = main_layerset.layer_set.count()
+            main_lyrs_ct = main_layerset.get_layers().count()
         else:
             main_lyrs_ct = 0
         mm_ct, mm_todo, mm_percent = 0, 0, 0
@@ -441,7 +441,7 @@ def update_item_lookup(self):
         multimask_ct, multimask_rank = 0, 0
         main_layerset = self.get_layerset("main-content")
         if main_layerset:
-            main_lyrs_ct = main_layerset.layer_set.count()
+            main_lyrs_ct = main_layerset.get_layers().count()
         else:
             main_lyrs_ct = 0
 
@@ -833,6 +833,7 @@ class Meta:
         null=True,
         blank=True,
     )
+    mask = models.PolygonField(blank=True, null=True)
     file = models.FileField(
         upload_to="layers",
         null=True,
@@ -922,7 +923,7 @@ def set_layerset(self, layerset):
                 logger.info(
                     f"Layer {self.pk} removed from existing multimask in LayerSet {existing_obj.pk}"
                 )
-            if existing_obj.layer_set.all().count() == 1:
+            if existing_obj.get_layers().count() == 1:
                 delete_existing = True
         self.layerset2 = layerset
         self.save(update_fields=["layerset2"])
@@ -1050,13 +1051,15 @@ def __str__(self):
     def layer_display_list(self):
         """For display in the admin interface only."""
         li = [
-            f"<li><a href='/admin/core/layer/{i.pk}/change'>{i}</a></li>"
-            for i in self.layer_set.all()
+            f"<li><a href='/admin/core/layer/{i.pk}/change'>{i}</a></li>" for i in self.get_layers()
         ]
         return mark_safe("<ul>" + "".join(li) + "</ul>")
 
     layer_display_list.short_description = "Layers"
 
+    def get_layers(self) -> Iterable[Layer]:
+        return self.layer_set.all()
+
     @cached_property
     def centroid(self):
         return Polygon.from_bbox(self.extent).centroid
@@ -1139,7 +1142,7 @@ def update_multimask_from_geojson(self, multimask_geojson):
 
     def save(self, set_tilejson: bool = False, *args, **kwargs):
         if self._state.adding is False:
-            extents = self.layer_set.all().values_list("extent", flat=True)
+            extents = self.get_layers().values_list("extent", flat=True)
             layer_extents = []
             for extent in extents:
                 if extent:
diff --git a/ohmg/core/signals.py b/ohmg/core/signals.py
index 32998936..00bd17c1 100644
--- a/ohmg/core/signals.py
+++ b/ohmg/core/signals.py
@@ -61,5 +61,5 @@ def handle_layer_deletion(sender, instance, **kwargs):
 
     # remove layerset if this was the last layer attached to it
     if instance.layerset2:
-        if instance.layerset2.layer_set.all().count() == 0:
+        if instance.layerset2.get_layers().count() == 0:
             instance.layerset2.delete()
diff --git a/ohmg/extensions/views.py b/ohmg/extensions/views.py
index aa5b1898..81741a38 100644
--- a/ohmg/extensions/views.py
+++ b/ohmg/extensions/views.py
@@ -41,7 +41,7 @@ def get(self, request, mapid, layerset_category):
                 "label": f"Mosaic of {ls.category.display_name.lower()}, {ls.map}",
                 "items": [
                     IIIFResource(i.pk, trimmed=trim, extended=extended).get_annotation()
-                    for i in [k for k in ls.layer_set.all()]
+                    for i in [k for k in ls.get_layers()]
                 ],
             }
         )
diff --git a/ohmg/frontend/svelte_components/src/components/Georeferencer.svelte b/ohmg/frontend/svelte_components/src/components/Georeferencer.svelte
index 59f904b6..bd362238 100644
--- a/ohmg/frontend/svelte_components/src/components/Georeferencer.svelte
+++ b/ohmg/frontend/svelte_components/src/components/Georeferencer.svelte
@@ -58,6 +58,7 @@
   export let MAP;
   export let MAIN_LAYERSET;
   export let KEYMAP_LAYERSET;
+  export let OTHER_MAPS;
   export let PARCEL_LAYER;
 
   let previewMode = 'n/a';
diff --git a/ohmg/georeference/views.py b/ohmg/georeference/views.py
index 045577ba..49f88c2e 100644
--- a/ohmg/georeference/views.py
+++ b/ohmg/georeference/views.py
@@ -22,6 +22,7 @@
 )
 from ohmg.core.models import (
     Document,
+    Map,
     Region,
 )
 from ohmg.core.storages import get_file_url
@@ -210,12 +211,23 @@ def get(self, request, docid):
         parcel_layer = region.map.get_locale().get_parcels()
         parcel_json = parcel_layer.serialize() if parcel_layer else None
 
+        place = region.map.locales.first()
+        other_maps = []
+        if place:
+            other_maps = list(
+                Map.objects.filter(locales__id__exact=place.id, hidden=False)
+                .exclude(pk=region.map.pk)
+                .values_list("identifier", "title")
+            )
+            other_maps = [{"identifier": i[0], "title": i[1]} for i in other_maps]
+
         georeference_params = {
             "CONTEXT": generate_ohmg_context(request),
             "REGION": region_json,
             "MAP": map_json,
             "MAIN_LAYERSET": main_layerset,
             "KEYMAP_LAYERSET": keymap_layerset,
+            "OTHER_MAPS": other_maps,
             "PARCEL_LAYER": parcel_json,
         }