Here is something provided by Ron, but we are uncertain as to when this came out. It appears to be a Spanish-language newspaper article promoting a tryout, possibly in 2009.
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In early April 2007 the CBL hosted an open tryout in Dallas for prospective players to make the 4 teams that season. We found a Wayback Machine (archive.org) snapshot of the Bay Area Toros website which lists the original press release issued by the league. The link to that snapshot is here: 2007 Continental Baseball League draft Dallas Texas
We attempted to make a PDF of this release, but the Archive.org snapshot header cuts off some of the list. You are still welcome to see that PDF here: 2007 CBL original tryout and draft PDF
Found some mentions of a September 2009 CBL tryout at Cabrillo College. Here is the PDF flyer:
Here is a mention from Santacruzlive.com:
Pro baseball tryouts at Cabrillo College
If you know of prospective players looking to be informed of independent pro baseball tryouts in 2018 and beyond then have them sign up here: http://www.independentbaseballtryouts.net/