wheatgrass. In the slightly moister ponderosa pine forests grasses such as pinegrass are found with a cover of shrubs including white spirea, common snowberry, and mallow ninebark. The Minidoka District is separated from the rest of the forest by the Snake River Plain, also known as Idaho's potato belt; snowmelt from the forest provides a steady supply of water to the plain. The Minidoka District is a part of the Basin and Range Province, and while much of the vegetation here is similar to the northern part of the forest, the presence of Rocky Mountain juniper is notable as well as is the occasional cactus plant. In these pinyon-juniper woodlands trees also include singleleaf pinyon, Utah juniper, and curl-leaf mountain mahogany. Idaho's rarest plant, the Christ's Indian paintbrush, is endemic to on upper elevations of Mount Harrison in the Albion Mountains in the Minidoka District. Davis' springparsley is also endemic to the Albion Mountains. Additionally, the forest contains potential habitat for the threatened Ute lady's tresses. Exotic species (also known as invasive or non-native species) are often unintentionally introduced by people traveling from outside the forest by sticking to vehicle tires, shoes, or cattle and are usually found near roadways, campgrounds, and other areas used by people. The Forest Service has an invasive species control effort that identifies and attempts to contain the further spread of non-native plants. Invasive plants of particular concern in the forest include spotted knapweed, yellow starthistle, rush skeletonweed, leafy spurge, and cheatgrass. The mountain pine beetle is a native insect species that is known to experience large outbreaks that infest forest groves, and is particularly common in areas with numerous lodgepole pines and fir trees. A large infestation occurred from 1995 through 2003, and the beetle wiped out areas of lodgepole pine in the SNRA, an area historically too cold for outbreaks to occur. Fauna Sawtooth National Forest is home to over 243 bird species, 78 mammals, 28 reptiles and amphibians, and 29 fish. Invasive zebra and quagga mussels are potential threats to the forest's aquatic ecosystems because they can spread rapidly and cover large surface areas, including human structures, thus altering ecosystems, removing native mussels and threatening native fish. Wolves were controversially reintroduced to the SNRA in the mid-1990s to restore the ecosystem stability that they provide as top predators. This included managing high elk populations, which had inhibited new vegetation growth. Opponents to