Katherine Heigl Weds Josh Kelley

SUNDAY DECEMBER 23, 2007 07:15 PM EST

With a light snow falling outside, Katherine Heigl exchanged vows with musician Josh Kelley in scenic Park City, Utah.

The private reception was witnessed by Grey's Anatomy costars T.R. Knight – who told PEOPLE it was "incredible and beautiful" – and Sandra Oh, as well as Private Practice star Kate Walsh and new husband Alex Young.

Taking place in a small, private tent at the Stein Eriksen Lodge, the nuptials lasted about 30 minutes in an area decked out in white flowers and white candles. A walkway from the tent to the nearby reception was lined with white candles, illuminating the fresh snow.

The ceremony was officiated by Unitarian minister Tom Goldsmith. Heigl walked down the aisle to an acoustic song written by Kelley and performed by a cello and guitar players. According to a source, the bride and groom wrote their own vows. The bridesmaids wore red.

The two met in 2005 when Heigl, 29, appeared in a video for Kelley's song "Only You." Kelley, 27, an Augusta, Ga., native, told PEOPLE in November that he was excited about marrying the actress. "It's about showing someone you love that you're actually capable of the ultimate commitment," he said. "We're madly in love and she makes me excited to become married and to have a family and spend my life with someone. We're fairly opposite but we also share a lot of the same values."

The couple spent the week before their wedding making last minute preparations. On Wednesday, they spent the day running errands in Los Feliz, Calif. and Heigl got her nails done at Fancy Nails. While there, she happily posed for photos before deciding on fire engine red polish for the big day. Afterwards, the two lunched at French bistro Figaro with Heigl's mom Nancy and Grey's costar T.R. Knight. On Friday, they met with Rev. Goldsmith at his church in Salt Lake. "Two friends were with them," says a source. "Katherine and Josh seemed happy and relaxed."

Guests for the wedding began arriving in Salt Lake on Thursday and prior to the ceremony, Heigl enjoyed a "really feminine and small" bridal shower with 15 friends. A rehearsal took place on Saturday. The actress recently told Vanity Fair that she had no misgivings about marriage. "It's a crapshoot. The odds are really bad, especially in this town," the actress says. "But I have a lot of faith in Josh, and I wanted to have that one day when I stand in front of my friends and my family and honor him and how important he is in my life."