What factors caused Denver prices to go up the last 2 decades?

[Marcus Auerbach]

Hello fellow Denver investors and agents! For those of you who have been doing this long enough to remember when Denver real estate was still cheap (like back in 2000): what happened that caused prices to continually go up?

Aparently you have so much pressure on the inventory that even rough parts of town gentrify? 

Is it a constraint in inventory? What is going on with new construction? With mountains to the west, why is the city not growing to the east, or is that considered too far away from downtown?

I am looking to gain a deeper understanding for the causes and to see if my home market may or may not be on the same path...

Thanks in advance!