Eric: I am not familiar with the area you mention but if you have observed Sharp-tailed Snakes there, I am interested in that such sightings would be new locality record for the species in this state.
What elevation have you observed both species and I assume that you are still in Jackson County. At any rate, I would be interested in taking both elevation and GPS locality readings for the sites at which you found both species.
I am retired so pretty free to travel anytime. If you willing to show me where you have observed Contia in particular on the south side of the pass in Oregon, you might contact me by email when the weather turns better the last part of March.