As a proxy record of climate, tree-ring chronologies have the advantage of being well replicated, exactly dated to the calendar year, and with numerically verifiable signals. We have used a Douglas-fir and a whitebark pine chronology from Idaho Climate Division 8 (Northeast Valleys) to reconstruct air temperature over the last millennium. The 857-year proxy record of July mean temperature shows decadal-to-centennial departures from the long-term average. Periods of extreme cooling are centered around AD 1300, 1340, 1460, and after AD1600. Higher than normal temperatures are found in the early 1400s, late 1500s, and in the 1930s. Both instrumental and proxy records do not show monotonic warming during the twentieth century. Low-frequency patterns are consistent with other temperature reconstructions for western North America based on ring-width series, and highlight the need to consider geographic differences alongside global averages