How often does Generic Routable (new style) get updated

How often should I reload a file for my area into the GPS and my computer? Can I contribute? Doing some motorcycle dual sport riding in my area and not all trails , roads are marked.

Thank you,

I assume you are asking about Garmin maps not about OSM itself. There is as special forum on this board for such questions.

I am talking about the OSM. I use Garmin Montana with the OSM Routable New. Not all roads, trails are on it. I ride trails. I was surprised one DNR trails section was on it. Can I contribute to other DNR trails I ride? I record tracks.

The Garmin sub forum for discussing Garmin suitable maps using data from OpenStreetMap is here
It is not an OSM site but rather a site whose product is derived from the OSM database in a similar way to these other Garmin suitable map sites that use data from the OSM database.

The map you refer to is here and below the blue map at the right side you will see the current map version date.
It is updated about monthly but does vary at times.

This is the OpenStreetMap site

You can contribute to the OSM map and here is an info link
You can upload your gpx tracks to the site and use those with a satellite imagery background to draw the ways or adjust already mapped items.