C# - Store Class Properties In Session And Use Of Session Handler - Is It Good Design

I have a class called EditMapUtilities. Here are some class properties that I want to persist:

public class EditMapUtlities
{
public static Boolean isInitialEditMapPageLoad
{
get { return SessionHandler.isInitialEditMapPageLoad; }
set { SessionHandler.isInitialEditMapPageLoad = value; }
}
// REST OF CLASS NOT GERMAIN TO DISCUSSION AND OMITTED
}

Here is my SessionHandler Class following the pattern from this post Static Session Class and Multiple Users:
using System.Web.SessionState;

public static class SessionHandler
{
private static HttpSessionState currentSession
{
get
{
if (HttpContext.Current.Session == null)
throw new Exception("Session is not available in the current context.");
else
return HttpContext.Current.Session;
}
}
//A boolean type session variable
private static string _isInitialEditMapPageLoad = "EditMapInitialPageLoad";
public static bool isInitialEditMapPageLoad
{
get
{
if (currentSession[_isInitialEditMapPageLoad] == null)
return true;
else
return (Boolean)currentSession[_isInitialEditMapPageLoad];
}
set
{
currentSession[_isInitialEditMapPageLoad] = value;
}
}
}

I am still learning OOAD. I want to keep relevant properties with relevant classes. I also want to keep all Session stored variables in one place for ease of maintenance and to encapsulate the session keys and calls. I feel like my design is too coupled though. How can I make it more loosely coupled? Is my editMapUtilities class too tightly coupled to the SessionHandler class? How would you do it better?