You can go to the PBS page on SkyWest online and click on bid info. It will give you the number of target line holders and show the number of reserve lines. Look at the seniority list and pick employee numbers and run them through the directory to see dates of hire.

What it won't show is guys senior enough to hold a line deliberately bidding reserve on purpose.-- Therefore someone that should be on reserve may be awarded a line or a composite schedule.

Should give you a general idea though.