diff --git a/etc/nshm/map-ceus.geojson b/etc/nshm/map-ceus.geojson
index 2849b85051e522b1c28297d13a9624fe52d85258..f3d6a8cd12b00896b0d03468553320e92621679b 100644
--- a/etc/nshm/map-ceus.geojson
+++ b/etc/nshm/map-ceus.geojson
@@ -3,7 +3,7 @@
   "features": [
     {
       "type": "Feature",
-      "id": "CLIP",
+      "id": "Extents",
       "geometry": {
         "type": "Polygon",
         "coordinates": [[
@@ -101,6 +101,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.1,
         "title": "NSHMP Central & Eastern US"
       }
     }
diff --git a/etc/nshm/map-cybershake.geojson b/etc/nshm/map-cybershake.geojson
index fbe79c9fa7313c5ce805a4b52f1bed614e779975..3e4426a4f990eb6cdbb7e17a3a515b34455d12fa 100644
--- a/etc/nshm/map-cybershake.geojson
+++ b/etc/nshm/map-cybershake.geojson
@@ -14,6 +14,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.1,
         "title": "Cybershake – Los Angeles Basin"
       }
     }
diff --git a/etc/nshm/map-la-basin.geojson b/etc/nshm/map-la-basin.geojson
index 20faf976e7311e0631803136eaf0b37ef4f28b94..f453a873bb962eda1c91d9759632ea1a50622252 100644
--- a/etc/nshm/map-la-basin.geojson
+++ b/etc/nshm/map-la-basin.geojson
@@ -14,6 +14,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.05,
         "title": "Los Angeles Basin – WGCEP 2007"
       }
     }
diff --git a/etc/nshm/map-new-madrid.geojson b/etc/nshm/map-new-madrid.geojson
index 20fbfd1a5c0205a7b284de26356b42b625308a10..57179b2543405c7c87914f92ee289cdceee911d9 100644
--- a/etc/nshm/map-new-madrid.geojson
+++ b/etc/nshm/map-new-madrid.geojson
@@ -14,6 +14,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.05,
         "title": "New Madrid Seismic Zone"
       }
     }
diff --git a/etc/nshm/map-nshmp-all.geojson b/etc/nshm/map-nshmp-all.geojson
index a1fae5377784f11711f500c3b83312050239d6dd..c1c6731b41da23d07c6dce6d0fcd680b9e8b8247 100644
--- a/etc/nshm/map-nshmp-all.geojson
+++ b/etc/nshm/map-nshmp-all.geojson
@@ -14,6 +14,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.1,
         "title": "Los Angeles Basin – WGCEP 2007"
       }
     },
@@ -30,6 +31,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.1,
         "title": "San Francisco Bay Area – WGCEP 2002"
       }
     },
@@ -46,6 +48,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.1,
         "title": "Wasatch Front – WGUEP 2013"
       }
     },
@@ -62,6 +65,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.1,
         "title": "New Madrid Seismic Zone"
       }
     },
@@ -78,6 +82,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.1,
         "title": "Puget Lowland"
       }
     },
@@ -103,6 +108,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.1,
         "title": "UCERF3 Production – 2014 NSHM"
       }
     }
diff --git a/etc/nshm/map-puget.geojson b/etc/nshm/map-puget.geojson
index c5357f37a2027afde4605d4c7b7597e145829900..f47d39035e4944dc39103a87866417445d7ed9bd 100644
--- a/etc/nshm/map-puget.geojson
+++ b/etc/nshm/map-puget.geojson
@@ -14,6 +14,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.05,
         "title": "Puget Lowland"
       }
     }
diff --git a/etc/nshm/map-sf-bay.geojson b/etc/nshm/map-sf-bay.geojson
index c395514f9ec916b0a7cfa0454392abfd6d46980d..f0a77e2f09a5b56f2f496b2da518f4387269292f 100644
--- a/etc/nshm/map-sf-bay.geojson
+++ b/etc/nshm/map-sf-bay.geojson
@@ -14,6 +14,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.05,
         "title": "San Francisco Bay Area – WGCEP 2002"
       }
     }
diff --git a/etc/nshm/map-ucerf3-nshm.geojson b/etc/nshm/map-ucerf3-nshm.geojson
index c2237639dbd08a9657404d5b5c19842afd77297b..fb54059367b0614477e1a963ee6c4819b1088d20 100644
--- a/etc/nshm/map-ucerf3-nshm.geojson
+++ b/etc/nshm/map-ucerf3-nshm.geojson
@@ -23,6 +23,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.1,
         "title": "UCERF3 Production – 2014 NSHM"
       }
     }
diff --git a/etc/nshm/map-ucerf3-relm.geojson b/etc/nshm/map-ucerf3-relm.geojson
index 96bbbb590fcdbe7b15c76032aeb84c9a39dcc1de..79faad20dca784ed9c2eb19fc235ada3c0d7bd4c 100644
--- a/etc/nshm/map-ucerf3-relm.geojson
+++ b/etc/nshm/map-ucerf3-relm.geojson
@@ -26,6 +26,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.1,
         "title": "UCERF3 Development – RELM Testing Region"
       }
     }
diff --git a/etc/nshm/map-wasatch.geojson b/etc/nshm/map-wasatch.geojson
index 70221e3166605808452224c824b0cf21cc0d4310..82b8cf5e85fe9fbb31a2488f1ab7d3833fbc9465 100644
--- a/etc/nshm/map-wasatch.geojson
+++ b/etc/nshm/map-wasatch.geojson
@@ -14,6 +14,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.05,
         "title": "Wasatch Front – WGUEP 2013"
       }
     }
diff --git a/etc/nshm/map-wus.geojson b/etc/nshm/map-wus.geojson
index ab9e8edbeaa96eaf499bfa5eb6de00f47de49508..db2dabb66b8bb56af4ffaa6789490e39f342ed57 100644
--- a/etc/nshm/map-wus.geojson
+++ b/etc/nshm/map-wus.geojson
@@ -3,7 +3,7 @@
   "features": [
     {
       "type": "Feature",
-      "id": "CLIP",
+      "id": "Extents",
       "geometry": {
         "type": "Polygon",
         "coordinates": [[
@@ -101,6 +101,7 @@
           ]]
       },
       "properties": {
+        "spacing": 0.1,
         "title": "NSHMP Western US"
       }
     }