A three-day multisport festival consisting of a sprint distance triathlon on Friday afternoon, Gran Fondos (road bike rides of varying distances) on Saturday and running races on Sunday.  Participants can enter individual events or take one of two “Eurekan” challenges.  What is “The Eurekan”?  The name is not only the moniker of the event, but also refers to participants who compete the ultimate challenge!  A “Full Eurekan” participant must complete the triathlon, 100-mile bike ride and the 10k run to be known as “The Eurekan:  There is also a Half Eurekan competition which is the triathlon, 62-mile bike ride and 5K run.  The triathlon is held on Holiday Island, just a few minutes from downtown Eureka Springs.  The finish line for the biking and running events are in the heart of Eureka Springs on historic Main St in front of the Eureka Springs City Courthouse.

More info here