The 2011 Mawddach Goldrush MTB Challenge will take place on March 13.
In its fourth year, the event is run over three laps of a 15km course at Coed y Brenin.
And while the overall distance has been reduced from 60km to 45km, the percentage of single track has been increased to include additional technical sections of the Tarw trail, making for an altogether more difficult ride.
Proceeds are donated to Wales Air Ambulance and Rotary International.
Entries are now open and can be made either individually or as a relay team.
For more information or to enter, head to www.mawddachgoldrush.org.uk