Penumbra

Directly "overlapping" the material world is a portion of the Umbra known as the the Penumbra. The Penumbra mirrors physical reality, but reality as it is "supposed" to be. Though divided, the two were once joined. The spirit world still touches the material one, for were it gone completely, Earth could not sustain life. Powerful actions on the physical plane send emanation into the spirit world. The most powerful of these psychic emanations ripple past the Penumbra into the Near Umbra, where they create whole realms. Such Realms often form based on a single idea or collection of legends. For example, the Nazi camps created hellholes with pits leading to Realm of Malfeas or Atrocity Realm, the atomic bombing sent the psychic reflection of dead zones into the Thousand Hells of the Yama Kings.
In the Penumbra, a toxic waste dump site will swarm with malevolent Banes, a city will be covered in cobwebs woven by Pattern Spiders, and a grove of trees will stand taller and wilder. A volcano eruption or a flaming factory could give birth to Fire Elementals.
The appearance of the Penumbra seems to be based on the viewpoint of the viewer. Werewolves will see it in a more animistic fashion, with an immense Moon dominating the sky (the Sun, conversely, tends to be much smaller), and everything represented by a spirit. Some mages may see it more representing ideals and concepts rather than spirits. Other mages (and the rare vampire who makes it here) will see things in a state of decay: a swollen red sun shining on crumbling buildings and rusting husks of cars. An uninformed observer may assume, based on description, that there are three different Penumbrae, one for each Umbra. This is a mistaken assumption, however: if three different travelers arrive in the Penumbra, each viewing a different "facet", they are still able to see and contact each other. Despite the varying perspectives, there is truly only one Penumbra.
For this reason, it is possible that the Shadowlands /Wasteland is simply one aspect of the Penumbra.