"If your average relative humidity was over about 25% ..."

That's excellent advice from Art Reblitz about the humidity change
in Colorado.  I suggest you purchase a high quality absolute humidity
gauge or use a sling psychrometer for measurements.  The hardware store
varieties leave much to be desired since they only poorly measure
relative humidity.

Adding a whole house humidifier to the supply plenum of a forced air
furnace will create a greater stability than any small humidifier unit
can.  We have an Aprilaire humidifier on the furnace plenum here at
our Lake Tahoe home at 7000 feet.  I tried the room humidifier first.

Ray Bauer
Tahoe City, Calif.