Further playing..............

In the Treeview_SelectedNodeChanged method I added

        If Not sender.SelectedNode.Parent Is Nothing Then
            If Session("Treeview") Is Nothing Then
                Session.Add("Treeview", TreeView1)
            End If
            Session("Treeview") = TreeView1

This enabled me to check the Treeview in my new content page.........

            If Not Session("Treeview") Is Nothing Then
                Dim tvPage1 As TreeView = CType(Session("treeview"), TreeView)
                Label1.Text = tvPage1.SelectedNode.Text
                Label2.Text = tvPage1.SelectedNode.Value
            End If

This properly displays the value of the last item selected in the treeview. However, when I tried to bring back the original treeview in the Master Page via.....

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        If Not IsPostBack Then
           If Session("Treeview") Is Nothing Then
                .
                .
             Build the Treeview
                .
                .
            Else
               TreeView1 = CType(Session("Treeview"), TreeView)
            End If
        End If
    End Sub

clicking on an item in the Treeview results in the content page showing the correct values for what was clicked........

but the Treeview is no longer visible.

I'm trying, but I still need a lot of help to get there..............Rich