Up, up and away. Utah home prices keep climbing.

At 17.55 percent, the state's house-price appreciation was nearly triple the national rate and was the highest of all states and the District of Columbia in last year's fourth quarter compared to the same quarter of 2005, according to a new report by the U.S. Office of Federal Housing Enterprise Oversight.

Wyoming ranked No. 2 at 14.29 percent, and Idaho came in third at 13.99 percent.

Some Utah cities posted even stronger gains.

The Provo-Orem and Salt Lake metropolitan areas ranked Nos. 3 and 4, respectively, for appreciation in the fourth quarter among 282 U.S. cities. Ogden placed No. 14 at 15.30 percent, while St. George showed appreciation of 12.30 percent, ranking No. 28.

"I think that the last two years have been very strong in our market after having three relatively flat years," said Debra Sjoblom, a real estate agent with Salt Lake-based Chapman and Richards. "I think we are still in a very stable situation. I think it's certainly a great appreciation but not so great that we're running any risk of having it tumble."

As recently as the second quarter of 2004, Utah ranked dead last among all states and the District of Columbia in house-price appreciation.

Nationally, home prices rose 5.87 percent in the fourth quarter compared to the same period in 2005. But several U.S. cities showed a retreat.

Santa Barbara, Calif., was down 4.20 percent in the fourth quarter compared to a year earlier. And the Reno-Sparks, Nev., area showed a nearly 1 percent drop in home prices for the same period. Of all states, only Michigan showed an overall decline in housing prices at 0.44 percent.

"In some sense, what we've seen over the last year or two has been unsustainable," said Andrew Leventis, an economist with OFHEO. "It was just a matter of when the appreciation rates were going to fall."

Leventis cautioned that Utah's double-digit price gains, like those in other states, will only last so long.

"Unless income growth really picks up in your area, 18 percent is definitely unsustainable over the long term," Leventis said. "But at the end of the day, Utah house prices relative to income are relatively affordable."

Utah's average wage in 2006 was $34,600, a 5.4 percent increase over the previous year, according to a state economic report. It was the highest level of wage growth in 14 years. However, per capita personal income in Utah is just 80 percent of per capita personal income nationally.

Dan Bodily of Lehi, owner of Blue Ridge Cabinets and a homebuilder, said he is unsure whether Utah's appreciation rates are sustainable.