diff --git a/examples/osgdem/osgdem.cpp b/examples/osgdem/osgdem.cpp
index 20d70c9cc..e77f64105 100644
--- a/examples/osgdem/osgdem.cpp
+++ b/examples/osgdem/osgdem.cpp
@@ -115,6 +115,7 @@ void processFile(std::string filename,
 		   osg::Matrixd &geoTransform,
 		   bool geoTransformSet,
 		   bool geoTransformScale,
+                   bool minmaxLevelSet, unsigned int min_level, unsigned int max_level,
 		   osg::ref_ptr<osgTerrain::DataSet> dataset) {
 
     if(filename.empty()) return;
@@ -139,6 +140,10 @@ void processFile(std::string filename,
 					      osgTerrain::DataSet::Source::PREFER_CONFIG_SETTINGS);
 		source->setGeoTransform(geoTransform);
 	    }
+            if (minmaxLevelSet) 
+            {
+                source->setMinMaxLevel(min_level, max_level);
+            }
 	    
 	    dataset->addSource(source);
 	}
@@ -152,7 +157,10 @@ void processFile(std::string filename,
 	for(i = dirContents.begin(); i != dirContents.end(); ++i) {
 	    if((*i != ".") && (*i != "..")) {
 		fullfilename = filename + '/' + *i;
-		processFile(fullfilename, type, currentCS, geoTransform, geoTransformSet, geoTransformScale, dataset);
+		processFile(fullfilename, type, currentCS, 
+                            geoTransform, geoTransformSet, geoTransformScale, 
+                            minmaxLevelSet, min_level, max_level,
+                            dataset);
 	    }
 	}
     }
@@ -327,7 +335,7 @@ int main( int argc, char **argv )
         return 1;
     }
 
-
+    unsigned int maximumPossibleLevel = 30;
 
 
     // read the input data
@@ -338,6 +346,8 @@ int main( int argc, char **argv )
     bool geoTransformSet = false; 
     bool geoTransformScale = false; 
     double xMin, xMax, yMin, yMax;
+    bool minmaxLevelSet = false;
+    unsigned int min_level=0, max_level=maximumPossibleLevel;
          
     int pos = 1;
     while(pos<arguments.argc())
@@ -501,11 +511,23 @@ int main( int argc, char **argv )
             std::cout<<"--zt "<<geoTransform(3,2)<<std::endl;
         }
 
+        else if (arguments.read(pos, "--levels", min_level, max_level))
+        {
+            minmaxLevelSet = true;
+            std::cout<<"--levels, min_level="<<min_level<<"  max_level="<<max_level<<std::endl;
+        }
+
         else if (arguments.read(pos, "-d",filename))
         {
 	    std::cout<<"-d "<<filename<<std::endl;
-	    processFile(filename, osgTerrain::DataSet::Source::HEIGHT_FIELD, currentCS, geoTransform, geoTransformSet, geoTransformScale, dataset);
+	    processFile(filename, osgTerrain::DataSet::Source::HEIGHT_FIELD, currentCS, 
+                        geoTransform, geoTransformSet, geoTransformScale,
+                        minmaxLevelSet, min_level, max_level, 
+                        dataset);
 
+            minmaxLevelSet = false;
+            min_level=0; max_level=maximumPossibleLevel;
+            
             geoTransformSet = false;
             geoTransformScale = false;
             geoTransform.makeIdentity();            
@@ -513,8 +535,14 @@ int main( int argc, char **argv )
         else if (arguments.read(pos, "-t",filename))
         {
 	    std::cout<<"-t "<<filename<<std::endl;
-	    processFile(filename, osgTerrain::DataSet::Source::IMAGE, currentCS, geoTransform, geoTransformSet, geoTransformScale, dataset);
+	    processFile(filename, osgTerrain::DataSet::Source::IMAGE, currentCS, 
+                        geoTransform, geoTransformSet, geoTransformScale, 
+                        minmaxLevelSet, min_level, max_level, 
+                        dataset);
 
+            minmaxLevelSet = false;
+            min_level=0; max_level=maximumPossibleLevel;
+            
             geoTransformSet = false;
             geoTransformScale = false;
             geoTransform.makeIdentity();            
@@ -522,8 +550,11 @@ int main( int argc, char **argv )
         else if (arguments.read(pos, "-m",filename))
         {
 	    std::cout<<"-m "<<filename<<std::endl;
-	    processFile(filename, osgTerrain::DataSet::Source::MODEL, currentCS, geoTransform, geoTransformSet, geoTransformScale, dataset);
+	    processFile(filename, osgTerrain::DataSet::Source::MODEL, currentCS, geoTransform, geoTransformSet, geoTransformScale, minmaxLevelSet, min_level, max_level, dataset);
 
+            minmaxLevelSet = false;
+            min_level=0; max_level=maximumPossibleLevel;
+            
             geoTransformSet = false;
             geoTransformScale = false;
             geoTransform.makeIdentity();            
diff --git a/include/osgTerrain/DataSet b/include/osgTerrain/DataSet
index aaed0a704..d27dff963 100644
--- a/include/osgTerrain/DataSet
+++ b/include/osgTerrain/DataSet
@@ -34,8 +34,10 @@ class OSGTERRAIN_EXPORT DataSet : public osg::Referenced
 {
     public:
 
+
+        static const unsigned int MAXIMUM_NUMBER_OF_LEVELS = 30;
+
         class Source;
-        
 
         struct SpatialProperties
         {
@@ -174,7 +176,9 @@ class OSGTERRAIN_EXPORT DataSet : public osg::Referenced
                 _sortValue(0.0),
                 _temporaryFile(false),
                 _coordinateSystemPolicy(PREFER_FILE_SETTINGS),
-                _geoTransformPolicy(PREFER_FILE_SETTINGS)
+                _geoTransformPolicy(PREFER_FILE_SETTINGS),
+                _minLevel(0),
+                _maxLevel(MAXIMUM_NUMBER_OF_LEVELS)
                 {}
         
             Source(Type type, const std::string& filename):
@@ -183,7 +187,9 @@ class OSGTERRAIN_EXPORT DataSet : public osg::Referenced
                 _filename(filename),
                 _temporaryFile(false),
                 _coordinateSystemPolicy(PREFER_FILE_SETTINGS),
-                _geoTransformPolicy(PREFER_FILE_SETTINGS)
+                _geoTransformPolicy(PREFER_FILE_SETTINGS),
+                _minLevel(0),
+                _maxLevel(MAXIMUM_NUMBER_OF_LEVELS)
                 {}
 
             void setSortValue(double s) { _sortValue = s; }
@@ -216,6 +222,15 @@ class OSGTERRAIN_EXPORT DataSet : public osg::Referenced
             
             void assignCoordinateSystemAndGeoTransformAccordingToParameterPolicy();
             
+
+
+            void setMinLevel(unsigned int minLevel) { _minLevel = minLevel; }
+            void setMaxLevel(unsigned int maxLevel) { _maxLevel = maxLevel; }
+            void setMinMaxLevel(unsigned int minLevel, unsigned int maxLevel) { _minLevel = minLevel; _maxLevel = maxLevel; }
+
+            unsigned int getMinLevel() const { return _minLevel; }
+            unsigned int getMaxLevel() const { return _maxLevel; }
+
             void setSourceData(SourceData* data) { _sourceData = data; if (_sourceData.valid()) _sourceData->_source = this; }
             SourceData* getSourceData() { return _sourceData.get(); }
             
@@ -279,6 +294,9 @@ class OSGTERRAIN_EXPORT DataSet : public osg::Referenced
             
             ParameterPolicy                             _coordinateSystemPolicy;
             ParameterPolicy                             _geoTransformPolicy;
+
+            unsigned int                                _minLevel;
+            unsigned int                                _maxLevel;
             
             osg::ref_ptr<SourceData>                    _sourceData;
             
diff --git a/src/osgTerrain/DataSet.cpp b/src/osgTerrain/DataSet.cpp
index 5bae2f584..d7fd46437 100644
--- a/src/osgTerrain/DataSet.cpp
+++ b/src/osgTerrain/DataSet.cpp
@@ -2416,12 +2416,18 @@ void DataSet::DestinationTile::readFrom(CompositeSource* sourceGraph)
     for(CompositeSource::source_iterator itr(sourceGraph);itr.valid();++itr)
     {
     
-        SourceData* data = (*itr)->getSourceData();
-        if (data)
+        Source* source = itr->get();
+        
+        if (_level>=source->getMinLevel() && _level<=source->getMaxLevel()) 
         {
-            std::cout<<"DataSet::DestinationTile::readFrom -> SourceData::read() "<<std::endl;
-            if (_imagery.valid()) data->read(*_imagery);
-            if (_terrain.valid()) data->read(*_terrain);
+            SourceData* data = (*itr)->getSourceData();
+            if (data)
+            {
+                std::cout<<"DataSet::DestinationTile::readFrom -> SourceData::read() "<<std::endl;
+                std::cout<<"    destination._level="<<_level<<"\t"<<source->getMinLevel()<<"\t"<<source->getMaxLevel()<<std::endl;
+                if (_imagery.valid()) data->read(*_imagery);
+                if (_terrain.valid()) data->read(*_terrain);
+            }
         }
     }