AUBURN, Wash. &ndash; Noosa Beach, marching inexorably toward a defense of his title in the Grade 3 Longacres Mile, will be a prohibitive favorite Sunday in the $50,000 Mount Rainier Handicap at Emerald Downs. Only four challengers were entered to face Noosa Beach, who has won six consecutive stakes races and seems to be getting better with each start.\r\nThe Mount Rainier, shortened from nine furlongs to 1 1/16 miles this year, is the final Emerald stakes race for older horses before the $200,000 Longacres Mile on Aug. 21. It has been an accurate barometer of Mile success &ndash; four of the past five Mount Rainier winners, starting with Flamethrowintexan in 2006, have gone on to capture the Mile. Noosa Beach won the race by more than four lengths last summer and then rolled to a popular victory in the Longacres Mile three weeks later.\r\nNoosa Beach has been on a remarkable roll for the team of trainer Doris Harwood and her husband Jeff, who&rsquo;s the owner, co-breeder, and front man for a traveling show that could take Noosa Beach to Churchill Downs for the $1 million Breeders&rsquo; Cup Dirt Mile in November. The Harwoods ponied up $25,000 to make Noosa Beach Cup eligible, and they&rsquo;ll go that route if their prized 5-year-old passes muster in the Mount Rainer and then the Mile. Noosa Beach signaled all systems go with a 46-second flat workout over four furlongs Wednesday. Gallyn Mitchell has the riding assignment.\r\nWhile the other four entrants have yet to crack Noosa Beach&rsquo;s armor this year, an upset is possible. Assessment, a troubled second in the 6 1/2-furlong Governor&rsquo;s Handicap in May and the only horse to defeat Noosa Beach over the past two years, has a fighting chance. Assessment was the toast of Emerald Downs in 2009, when he captured the Longacres Mile and two other stakes, but he has just two victories in his past 10 starts.\r\nWinning Machine, Noosa Beach&rsquo;s chief adversary during their 3-year-old season in 2009, closed to finish second behind Noosa Beach in the one-mile Budweiser Handicap on June 19. He&rsquo;ll have the services of Emerald&rsquo;s leading rider, Leslie Mawing, for trainer Frank Lucarelli, who has won 27 stakes races in the track&rsquo;s 15-plus seasons.\r\nSaratoga Boot, winner of the 2010 Emerald Derby, could be formidable in his third start of the year. He made a bold move on the far turn in the Budweiser to reach equal terms with Noosa Beach, but faded in the stretch to finish third.