At that high of an altitude, it's all in the jets. Less air up there means you were running on the rich side.
And 9000ft!! Highest I've been on the bike was just about 3500ft on my Skyline Drive ride.
The highest spot in PA is only 3213ft (Mt. Davis).
I would think there's gotta be someone here who rides higher elevations often enough to help. A previous member, Insured Disaster, was at pretty good heights, but he's long gone from here now.
AKA: Tim & 'The Adventure Cycle' VROC #24567, NEVROC, SteelCity VROC
"When life throws you curves,
Aim for the apex."