By Curtis Anderson The Register-Guard

Published: February 12, 2008 04:38AM

With his Olympic ticket already secured, Eugene distance runner Dathan Ritzenhein will focus on cross country for the next six weeks.

Ritzenhein, who earned a spot on the U.S. team and will run the marathon at the 2008 Beijing Olympics after placing second at the Trials in New York City last November, is set to compete in the U.S. Cross Country Championships in San Diego on Saturday.

Ritzenhein, 25, joins a large field of entrants in the men’s open 12K race at Mission Bay Park at 2 p.m.

He needs a top-six finish to reach his goal of qualifying for the IAAF World Cross Country Championships in Edinburgh, Scotland, on March 30. Ritzenhein won the U.S. cross country title in 2005.

The former NCAA cross country champion at Colorado won’t be in top condition.......