The recent tread separation problems with Firestone tires is a good reminder to check tire pressures regardless of the type tires on your vehicle. Hi! I'm Don Alexander for the Mountain Driver on KBHR.  The biggest cause of tire problems is under-inflation.  But under-inflation can also cause serious handling problems.
Low tire pressure allows the sidewall of the tire to flex more.  This affects the handling characteristics of the tire, reducing traction for braking and cornering.  This reduced pressure also causes increased tire wear.  And heat buildup in the tire due to low pressure can cause tire failure, not a good thing in the mountains. 
Tire pressures should be set at the level recommended by your vehicle manufacturer.  You can find this information in your owner's manual or on an information tag, usually located in the glove box or door jam.  Maximum inflation pressures are also listed on the sidewall of the tire.  If you have no other information, use this as a guideline, but ever exceed this maximum inflation pressure.  For heavier loads, the pressure should be slightly higher than for lighter loads.  This reduces sidewall flex and helps keep the vehicle stable.
While pressure gauges at the service station work, it is a good idea to carry an inexpensive tire pressure gauge in the glove box and check your pressures often, especially before traveling up or down the mountain.  And if you notice unusual tire squeal or if the steering pulls in one direction, it's a good sign of low tire pressures.  Check them as soon as possible for a safe trip. This is Don Alexander for The Mountain Driver on KBHR 93.3 FM.