Tracks can be closed for many reasons however it is typically due to rainfall.
When trails are soft and squishy your tires create ruts. When those then dry out they are now part of the trail which create less than desirable conditions to ride in and often degrades further over time.
Many people volunteer their time to maintain the tracks so please respect this by avoiding trails when they are set to avoid or closed.
Information is sourced every hour from the CCC Track Status page.
This system in unaffiliated with the CCC
Website by Ben Young