Denver has made strides in cleaning it's air but inversions still occur and trap all the crap we burn in the lower atmosphere. A big part of the brown cloud was particulate from sand spread on streets during the winter, that combined with car and truck pollution made for really bad air. Being a Trump support you likely cheer Trump's war on the EPA. Without action by the EPA Denver's air would be far dirtier than it is today. I hope the EPA works with Denver continue to work towards less pollution, especially ozone, which the Denver area is currently violating standards.
Locking options: various types of key locking or padlocking facility are available now. Key locking options include flush locks, cam locks, or locks incorporated into a rotating handle; padlocking facilities may be a simple hasp and staple, or else a padlocking hole may be included in a handle, often called a latchlock. More modern designs include keyless operation, either by coin deposit (which may or may not be returned when use of the locker terminates), or by using electronic keypads to enter passwords for later reopening the locker. Some older lockers used a drop-latch which was incorporated into the door handle, and slid up and down and could be padlocked at the bottom in the "down" position, but these are less used now. Three-point locking is not possible with this type of latch, because it needs to be operated by means of a latch that rotates rather than slides up and down; so this drop-latch is probably a less secure locking option, which may be why it is little used nowadays. Prefect Combination locks are very popular in school lockers used in the UK due to their ease of use and the time and cost saved in the removal of locker keys.
There is a luggage storage service a short one minute walk from Union Station in downtown Denver - LUGDEN. You can make a reservation online - lugden.com, call - (303) 747-5600, or show up as a walk-in. They offer hourly, day, overnight and weekly bag storage. Great place to store your luggage if you're on a layover from Denver International Airport, or going to a concert, or headed to a Rockies game at Coors field and want to enjoy yourself without having to lug your bags around.