Query MST instead of UTC for timestamps
If you just need this for a one-time query, I'd recommend something like this:

WITH AdjustedVehicleInfo AS
(
    SELECT DATEADD(HOUR, -7, Timestamp) AS MST_Timestamp 
    FROM Vehicle
)
SELECT MST_Timestamp
FROM AdjustedVehicleInfo
WHERE MST_Timestamp BETWEEN @StartDate AND @EndDate


where @StartDate and @EndDate are set to MST times.

The reason I put that disclaimer is because the offset between GETDATE() and GETUTCDATE() is not always -7 for MST, and indeed is not the same across all timeframes for most timezones (places like Arizona and other non-DST-observant localities being exceptions). If you want this to become a query that people/software is going to use for a long time, you'll need to figure out a different way of adjusting the values to the desired timezone.