Access a Master Page Property from content page CodeBehind

[Matt]

I am trying to access a property that I have created inside a Master
Page. However all instruction that I have found shows them accessing
the property from a .aspx page not a .aspx.vb page.

My master page (Default.master, with _default as the codebehind class)
contains the following property:

Public Property ParkID() As Integer
Get
Return ddParks.SelectedValue
End Get
Set(ByVal value As Integer)
ddParks.SelectedValue = value
End Set
End Property

I am trying to reference this property from index.aspx (or more
specifically the code behind of index.aspx.vb). Right now I am simply
trying to write out the value, before I do anything with it. I read
that I could do this " CType(Me.Master, _default).ParkId " however the
"_default" type is causing an error as it cannot find it. I am not
sure how I can get my index class to see the _default.

Any help wopuld be very much appreciated, as I am just starting to use
..NET 2.0 and trying to begin migrating some of our software.

Imports System.Web.Configuration

Partial Class index
Inherits System.Web.UI.Page

Private strSQL As String
Private rs As DataSet

Protected Sub Page_Load(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Me.Load

Response.Write("Page Load<br>")

Response.Write("ID:" & CType(Me.Master, _default).ParkId &
"<br>")

End Sub

Thanks
Matt