<esri:Map x:Name="MyMap" WrapAround="True" Background="White">
<esri:ArcGISTiledMapServiceLayer ID="PhysicalTiledLayer"
Url="http://services.arcgisonline.com/ArcGIS/rest/services/NGS_Topo_US_2D/MapServer"/>
<esri:GraphicsLayer ID="MyGraphics" >
<esri:GraphicsLayer.Graphics >
<esri:Graphic Symbol="{StaticResource RedMarkerSymbol}" >
<esri:MapPoint X="-140.9" Y="63.391" />
</esri:Graphic>
</esri:GraphicsLayer.Graphics>
</esri:GraphicsLayer>
</esri:Map>