Most trails in the Midwest can be grouped into discrete riding areas. By this I mean it is typical to drive to a parking lot, park and ride 6 different trails in one trail area. It would be nice to be able to group a set of trails that are within the same trail system. This would also allow for conditions for the whole trail system to be posted rather than just for each individual trail.
Have you checked out the directory feature? Links to each state are on the main page and drill down to areas. I think the level of sub-grouping is a little excessive and should be flattened out a lot (maybe just state and riding area or 1 layer max in between), but I think they are already doing something similar.
Alec is spot on with his comment. The App is lacking the important information that the website has regarding the name of the trail cluster. (The highest rated trail in our area, for example, is identified on the app as "the blue loop")
Just a quick note from me. Though we've reduced the emphasis on these areas for the app, they should still be searchable by using the magnifying glass icon in the upper right and then tapping "Locations" instead of "Rides/Trails". This will reframe the map over that specific area, where you can tap into trails or rides or access the Trail List to see the list view. If there are areas that we're missing on the site, please let us know!