Your matchbook is a great visual representation of the East-side-only Virginia Street restriction on gambling in Reno at that time.
See the interior map in the matchbook.

A discussion about Ernie Primm on 3/31 by Rich Burgel describes the "red line" barrier of the time that Primm's Primadonna club finally defeated.
See: http://www.thechipboard.com/index.cgi/page/5/md/read/id/1334493/sbj/rich-good-pictures-and-stories-another-picture/

Interesting history on that matchbook.