Seeking storage in Denver in June

[BillsBayou]

I'm going to the ABS Bonsai convention in Denver this June. Our plan is to be camping before and after the convention. The problem is the roof-top luggage pod, the inverter generator, and gas can. The carrier won't fit in the underground garages at the hotel and botanical garden. Would anyone in the Denver area be nice enough to store these items from Thursday to Sunday? It doesn't need to be inside.

Other suggestions for the problem would be welcome.