This unconventional way of dividing up a species' protections is based on a controversial memo issued by a Bush appointee that allows the Fish and Wildlife Service to protect a species within a portion of its range rather than throughout its entire range.
Interestingly, this same approach has been used with the gray wolves in the northern Rocky Mountains where endangered species protections have been removed in Idaho and Montana, but retained in Wyoming.
What is it about Wyoming that makes you either endangered or not in a manner different than your neighbor?
In the case of the Preble's mouse, Wyoming contains the mouse's most northern habitat as well as its highest elevation habitat - both of which are likely to become increasingly important to the mouse with continued global warming. If part of a species' range is important to that species' survival, it's important to protect.
So today NRDC, along with a coalition of partners, is challenging the decision to remove protections from the mouse in the state of Wyoming. This case is about restoring full protections to the Preble's meadow jumping mouse, but it's also about protecting endangered wildlife in general. If we whittle away the area that these species need to survive, we'll soon find they have nowhere to stand - or jump, as the case may be.