It looks like I'll be needing to store my van for the winter. Anything I should do for prepping to store? The van will be in the western slope of colorado in sub-zero temps from November through March.
That’s not really very long, but if you expect it to be sub-zero when you pick it up I would suggest an anti-gell additive be added to your fuel tank before your final drive into storage in case your fuel retailer is still on a summer blend. Storing with a full fuel tank will discourage condensation collecting inside the fuel tank.
You can pull the negative terminal from the battery to minimize battery drain, and connect a maintenance charger to the battery if at all possible.
If you are nearing the end of your oil change interval you may wish to move it forward and change oil just prior to storage.
Check tire pressures, and consider covering your wheels to protect from sunlight, putting shades in the windows, rodent damage can be an issue, as can mildew, etc. but these are typically longer term storage issues (except rodents).
Leave the tank as full as possible, check your antifreeze mix if not certain. disconnect battery negative terminal, and top up battery if desired. a 10w panel on the dash, or a float charger plugged into a 120V outlet.
Make sure windshield washer fluid is low temp rated (so it doesn't freeze).