I thought I’d start a new thread now that the PGTH is up and running.
The website is at http://gps.dauphin.ca. It appears they’re not using GC.com, but they do refer to the “200 caches in Manitoba”. They ask you to setup an ID through their web site to participate in the contest. To play, you must record a code word from the cache. Cache locations are at http://gps.dauphin.ca/cache.php, The notation’s wrong, but that's a common mistake.
Their web site links to the MBGA site and GC.com (and some others) as resources.