Seasonal hiring: what is paying well this year? after 13 years as a data-entry clerk

A retailer and two warehouses near Salt Lake City are hiring seasonal staff. There are 13 people counting on me, so I am trying to be careful. I would like to avoid a gap in my résumé. Is it worth applying to several at once?

Keep a list of supervisors' names. A reference from one of them helped me land my next job.

I was converted after one season because I showed up every day and volunteered for extra shifts. Managers remember that.