diff --git a/src/osgPlugins/ive/IveVersion.h b/src/osgPlugins/ive/IveVersion.h
index 74c8c15f4..667a6a278 100644
--- a/src/osgPlugins/ive/IveVersion.h
+++ b/src/osgPlugins/ive/IveVersion.h
@@ -35,8 +35,9 @@
 #define VERSION_0024 24
 #define VERSION_0025 25
 #define VERSION_0026 26
+#define VERSION_0027 27
 
-#define VERSION VERSION_0026
+#define VERSION VERSION_0027
 
 /* The BYTE_SEX tag is used to check the endian
    of the IVE file being read in.  The IVE format
diff --git a/src/osgPlugins/ive/Layer.cpp b/src/osgPlugins/ive/Layer.cpp
index 4c238a694..73aa79b8c 100644
--- a/src/osgPlugins/ive/Layer.cpp
+++ b/src/osgPlugins/ive/Layer.cpp
@@ -50,6 +50,11 @@ void Layer::write(DataOutputStream* out)
 
     out->writeUInt(getMinLevel());
     out->writeUInt(getMaxLevel());
+
+    if (out->getVersion() >= VERSION_0027)
+    {
+        writeValidDataOperator(out,getValidDataOperator());
+    }
 }
 
 void Layer::read(DataInputStream* in)
@@ -83,6 +88,10 @@ void Layer::read(DataInputStream* in)
     setMinLevel(in->readUInt());
     setMaxLevel(in->readUInt());
 
+    if (in->getVersion() >= VERSION_0027)
+    {
+        setValidDataOperator(readValidDataOperator(in));
+    }
 }
 
 void LayerHelper::writeLayer(DataOutputStream* out, osgTerrain::Layer* layer)
@@ -196,3 +205,56 @@ osgTerrain::Locator* LayerHelper::readLocator(DataInputStream* in)
     
     return locator;
 }
+
+void Layer::writeValidDataOperator(DataOutputStream* out, osgTerrain::ValidDataOperator* validDataOperator)
+{
+    if (validDataOperator)
+    {
+        out->writeBool(true);
+        osgTerrain::ValidRange* validRange = dynamic_cast<osgTerrain::ValidRange*>(validDataOperator);
+        if (validRange)
+        {
+            out->writeInt(IVEVALIDRANGE);
+            out->writeFloat(validRange->getMinValue());
+            out->writeFloat(validRange->getMaxValue());
+        }
+        else 
+        {    
+            osgTerrain::NoDataValue* noDataValue  = dynamic_cast<osgTerrain::NoDataValue*>(validDataOperator);
+            if (noDataValue)
+            {
+                out->writeInt(IVENODATAVALUE);
+                out->writeFloat(noDataValue->getValue());
+            }
+        }
+    }
+    else
+    {
+        out->writeBool(false);
+    }
+}
+
+osgTerrain::ValidDataOperator* Layer::readValidDataOperator(DataInputStream* in)
+{
+    bool hasOperator = in->readBool();
+    if (!hasOperator) return 0;
+    
+    int id = in->peekInt();
+    if (id==IVEVALIDRANGE)
+    {
+        id = in->readInt();
+        float minValue = in->readFloat();
+        float maxValue = in->readFloat();
+        return new osgTerrain::ValidRange(minValue,maxValue);        
+    }
+    else if (id==IVENODATAVALUE)
+    {
+        id = in->readInt();
+        float value = in->readFloat();
+        return new osgTerrain::NoDataValue(value);
+    }
+    else
+    {
+        return 0;
+    }
+}
diff --git a/src/osgPlugins/ive/Layer.h b/src/osgPlugins/ive/Layer.h
index f85189015..2ba6f1ac5 100644
--- a/src/osgPlugins/ive/Layer.h
+++ b/src/osgPlugins/ive/Layer.h
@@ -36,10 +36,14 @@ class LayerHelper
 class Layer : public osgTerrain::Layer, public ReadWrite 
 {
     public:
-	void write(DataOutputStream* out);
-	void read(DataInputStream* in);
+    void write(DataOutputStream* out);
+    void read(DataInputStream* in);
+
+    void writeValidDataOperator(DataOutputStream* out, osgTerrain::ValidDataOperator* validDataOperator);
+    osgTerrain::ValidDataOperator* readValidDataOperator(DataInputStream* in);
 };
 
+
 }
 
 #endif
diff --git a/src/osgPlugins/ive/ReadWrite.h b/src/osgPlugins/ive/ReadWrite.h
index 8306f7281..c15b5ac3e 100644
--- a/src/osgPlugins/ive/ReadWrite.h
+++ b/src/osgPlugins/ive/ReadWrite.h
@@ -130,6 +130,9 @@ namespace ive {
 #define IVEPROXYLAYER                   0x00200007
 #define IVETERRAINTECHNIQUE             0x00200008
 #define IVEGEOMETRYTECHNIQUE            0x00200009
+#define IVEVALIDDATAOPERATOR            0x0020000A
+#define IVEVALIDRANGE                    0x0020000B
+#define IVENODATAVALUE                    0x0020000C
 //#define IVETERRAIN                      0x0020000A
 
 // osgFX classes