ALONG THE YUKON RIVER — The midsummer air is hot after a long day of sun and stillness in the middle river village of Grayling, and the cutbanks seem to slouch closer toward the Yukon River below. Rachel Freireich says her mother moved here permanently from the Athabaskan village of Holikachuk, up a nearby tributary, in the 1960s to be closer to schools and salmon eddies.