List of AKC Basset Field Trials
UKC has beagle but no basset events
AHBA hunt schedule
You will not find one very close the closest being MO
You can check with local beagle clubs there is the occasional open minded club that will all a member with basset. You wont be able to trial but it does give you grounds to train and help in training with member that have done it before.
If you are versed in hunting with bassets and have five like minded friends and family you can start your own AHBA club an run your own field trials, Dean can help you in that regard.
I feel for Ya I have to travel 6+ hrs for the closest field trial and the training grounds are highly limited in the area.