SPORTS What: Steamboat Springs hosts the 2008 USA Trail Championships, with a 12K men's loop as well as an 8K women's and junior loop. Why: Pump up your running season. Each race follows the same intense trail loop, which starts flat, then cuts uphill on single track and ski runs, before dropping into rodeo grounds. Bonus: An all-you-can-eat Italian dinner opens the festival Saturday night, and a post-race brunch comes courtesy of Qdoba. Details: Sun 8:30 am. Steamboat Springs' rodeo grounds, 501 Howelsen Pkwy., Steamboat Springs. $35. For more information, visit www.runningseries.com/races/championships.php#race. THEATER What: The 19th-century London legend about a manic barber bent on killing his wife's kidnapper comes to life in Sweeney Todd, a dark and imaginative musical. Why: Stephen Sondheim, who wrote lyrics for West Side Story and A Funny Thing Happened on the Way to the Forum, is the mastermind behind this show's music and lyrics. Bonus: Sunday's Sweeney Todd VIP Evening (6 p.m., $225) begins with cocktails, appetizers, and dinner, and ends with fantastic orchestra seats for the show. Details: Through June 29. Wed-Fri 8 p.m.; Sat 2 p.m., 8 p.m.; Sun 2 p.m., 7:30 p.m. The Buell Theatre, 1050 13th St. $20-$90. For more information, call 303-893-4100 or visit www.denvercenter.org.