You pay $20 extra per year fort eh AHA competition card, but the endurance
rides that are also AHA sanctioned do not charge extra for you to be cross
entered. That is only true when it is a AHA Regional or National
Ride. So yes- that gets you eligible in Region 12 for the AHA
Region Challenge to try and get awards.
The other pluses to the competition card are that it gets you an additional
liability coverage - so if your horse bites someone, gets out in traffic causes
a wreck etc... you have this extra liability insurance to help you out.
You also can log your training hours with AHA in the Frequent Rider program
(free to members) and earn cool stuff that way.
You should be able to check it out on the AHA website - Hope that helps
=)