Washington ( CNN ) -- The parents of missing U.S. serviceman Bowe Bergdahl led the Rolling Thunder ride in Washington on Sunday , trailed by the roar of what was estimated to be hundreds of thousands of motorcycles . The annual Memorial Day weekend ride , now in its 25th year , is held in remembrance of prisoners of war and those missing in action . Bergdahl , a 26-year-old army sergeant , was captured in Afghanistan in 2009 after he finished his guard shift at a combat outpost in southeastern Paktika province . Security Clearance : Parents reveal secret talks with Taliban . `` Bowe , your family has not forgotten you , your hometown has not forgotten you . Your state of Idaho has not forgotten you , and thanks to all of you here today , Washington D.C. has not forgotten you , '' his father , Robert Bergdahl , told a cheering crowd . `` We love you , we are proud of you . Stay strong , never give up . We pray for the day that we welcome you home , '' he said . Flanked by riders wanting to offer support for the safe return of his son , Bergdahl spoke separately to CNN . He sported a long beard and wore a bandana imprinted with `` POW . '' His son 's official status is listed as `` missing/captured . '' `` The beard is a chronology , '' Bergdahl said , `` of my son 's captivity since June 30 , 2009 . '' Since his capture by Taliban militants , four videos of the Idaho native have been released , living proof of his well-being . But the last video was sent in February 2011 , and it 's unclear where Bergdahl is being held now , according to John Wagner , a spokesman for U.S. Central Command . `` We are still searching for him , '' said Wagner . `` We are actively looking for leads and information on his whereabouts and his condition . '' Bergdahl 's parents have spoken infrequently to the public to prevent comprising any negotiations that may be taking place . People participating in Sunday 's rally expressed support and encouragement for the Bergdahl family . Retired army Sgt . Kevin Coffey rode in on his Ultra Classic copper pearl Harley Davidson from North Carolina with the Rolling Thunder Chapter 7 , the group that sponsored the Bergdahl 's participation this year . `` I would hope that he would know that he is not forgotten , that somebody is looking for him now , '' said Coffey . Wayne Daniels , retired from the Army , outfitted his handcrafted Model T car in honor of soldiers lost in action and missing . He choked up when describing the moment his NC7 Rolling Thunder chapter asked him to drive Bergdahl 's parents in the lead vehicle . His three children and girlfriend did n't hesitate to give up their usual seats and stand on the sidelines and watch this year . `` I want to make ( people ) aware of who we still have missing , '' said Daniels . Adam Levy contributed to this report .
Bowe Bergdahl disappeared in June 2009 in Afghanistan . His parents lead the Rolling Thunder ride . Robert Bergdahl 's message to his son : `` Stay strong , never give up ''