Interior Alaska-Yukon lowland taiga. Their lands are located in different two ecoregions: The south of Tanana River, called Tanana-Kuskokwim Lowlands and this ecoregion forms an arch north of the Alaska Range and Lime Hills. Native people of the lowlands are mainly Koyukon, Tanana, and Kuskokwim Athabaskans. Main communities are Fairbanks, North Pole, Tok, and Delta Junction. The north of Tanana River, called Yukon-Tanana Uplands and this ecoregion forms are rounded mountains and hills located between the Yukon and Tanana Rivers and spanning the Alaska-Yukon Territory border. Native people of the uplands are Tanacross, Tanana, and Hän Athabaskans. Main communities are Fox, Ester, and Eagle. Tanana Athabaskans were semi-nomadic hunter-gatherers who moved seasonally throughout the year within a reasonably well-defined territory to harvest fish, bird, mammal, berry and other renewable resources. The Tanana territories generally is a mosaic of open and closed spruce forests covering the low gradient outwash slope between the Alaska Range and the flats and ridges north of the Tanana River. The economy of Tanana Athabaskans is a mixed cash-subsistence system, like other modern foraging economies in Alaska. The subsistence economy is main non-monetary economy system. Cash is often a rare commodity in foraging economies, because of lack of employment opportunities or perceived conflicts in the demands of wage employment and subsistence harvesting activities. The primary use of wild resources is domestic. Wild resource use in many Athabaskan villages is overwhelmingly for domestic consumption, since commercial fishing in Alaska is absent. Commercial fishing and trapping patterns are controlled primarily by external factors. The state's limited entry system, operational by 1974 (after ANCSA), limits the number of available fishing permits for commercial salmon (esp. the Pacific salmon Oncorhynchus species for salmon cannery) fishing. In Nenana, about one-third of households have a permit. Most (70%) sample households with a permit used. Those with a permit that did not fish commercially, did fish for subsistence. Hunting was associated with seasonal movements along trails and frozen rivers, particularly as bands moved between rivers and uplands. The primarily hunting animals for Tanana Athabaskans are big animals (caribou, moose, and wild sheep). Most valuable hunting animal is the caribou (subspecies Rangifer tarandus granti, Lower Tanana , Tanacross , Upper Tanana ). The caribou was the most important food animal in the Upper Tanana before the coming of the non-natives and resultant disintegration of the original nomadic patterns. The economic life of the Upper Tanana