Nearly two weeks ago, in the New York Times, there was a brief mention of northwestern Argentina, an area that gets plenty of European visitors but relatively few North Americans - despite its remarkable resemblance to the Four Corners area of Colorado, Utah, Arizona and New Mexico. The author of the article actually consults with Ian Mount, a U.S. journalist who writes the excellent Buenos Aires blog Good Airs. Ian, whom I've never met though he lives only a few blocks from me in Buenos Aires - somehow our schedules have never meshed - has some good suggestions including a visit to Estancia Colomé (pictured here) near the town of Molinos, in Salta province. If staying at Colomé is beyond your budget, it's still worth a detour to sample their outstanding wines.
Ian also mentions, as I would, that travel in this region is far more reliable by overnight buses than by air, as Aerolíneas Argentinas is still going through an awkward transition to state ownership. Flights are few to the northwest, so if you miss you'll likely have to wait an entire day for the next.