Marshall King is the creator of NTX Open H2O , a a website with information on open water swimming training and racing in Texas, New Mexico, Oklahoma, Arkansas and Louisiana. He joined Team in Training in 2003 and trained as a racewalker to walk his first half marathon, Virginia Beach Rock N Roll Half. He continued walking half marathons and full marathons. 18 months, he walked his first ultramarathon, The Heartland 50 mile ultra and began walking ultramarathon distances from 50k to 100 miles. In November, 2005, he became the 61st American to walk 100 miles in 24 hours (100.2 miles in 23:42) and became a Centurion.