Looks like you were up on Sulphur Mountain.
The main issue is a lack of contrast. This can often be helped, as Sparky did, by using a 'levels' adjustment and moving the black point & the white point. A curves adjustment helps the mid-tones. The boost to saturation was needed as well. Some software (Lightroom for example) has a clarity adjustment, which would help as well.
If you were shooting this again, I'd suggest lowering your exposure a little bit. The shadows would probably turn black, but that's not a big deal if the rest of the shot turns out better.
Also, a polarizing filter would have been great in this situation. It can darken blue skies, making the clouds pop out more...and probably a few other enhancements as well.
But we also need to consider the time of year, time of day and weather etc....and how those affect air quality. Late summer is typically a terrible time for air quality...especially on a hot day...especially if it hasn't rained. That's likely why there is so much haze in the image...there is just so many particles in the air that when you shoot though so much air, the photos will be hazy.