I assume that Barometer you were looking at was corrected. A baro of 29 at 2700' would be a record I imagine. The actual is much lower. Just like watching TV and seeing the weather. They always list the corrected barometer not the actual reading. To standardize the number and as to not confuse people. I am not a weather man by any means but running .90 stuff you learn a lot about it for sure. Pilots can probably explain it better.
Here is the abridged version
Most of the barometric pressure values that are listed on weather web sites are corrected to sea-level. This is done to standardize the values so that the altitude where the measurement was made does not significantly affect the result.
Barometric pressure that is not corrected to sea-level is usually referred to as absolute barometric pressure (the "absolute" term is what differentiates between the two) or absolute atmospheric pressure. The absolute atmospheric pressure is the actual pressure at the location where the measurement is taken from. All barometers, whether they are mercury-filled, aneroid or other designs, are affected by altitude because atmospheric pressure reduces with vertical distance from the Earth. If a barometer is moved upwards from nominal sea level its readings should reduce roughly by 1 hPa (1 mbar) for every 10 metres increase in altitude but note that the rate-of-change of pressure with altitude itself reduces significantly and non-linearly with altitude
