Are Ray and Elfriede Prefontaine Steve Prefontaine parents still alive?

no, they died october 27 2001 (incorrect previous answer)

Ray died on December 21, 2004.

Elfriede is still alive as of August 2010. She is 85-years-old and attended the Prefontaine Classic this year:

http://www.registerguard.com/csp/cms/sites/web/news/cityregion/24984677-41/prefontaine-meet-track-field-saturday.csp