The 10K, 5K, & Fun Run/Walk events are all part of a three-day multisport festival consisting of a sprint-distance triathlon on Friday afternoon, road bike tour rides and races on Saturday and running races on Sunday.
There is even a Eurekan category competition. Either the Full or Half Eurekan. See event website for full details - http://www.eurekasportsfestival.com/eurekan.htm
see event website for full details