MOAB — The flow of visitors to Utah's national parks has started, this year a little earlier than last, and next year, it's expected to start a little earlier than this year.

The feeling is that the so-called "shoulder seasons" or visits in the spring and fall are starting sooner and ending later.

One explanation is visitors are discovering that spring and fall are perfect times to see the natural wonders. The parks are not as crowded, the traffic not as congested, chances of snagging a campsite are much greater and temperatures are more comfortable.

Another reason for an increase in spring visits is the parks change colors. Added to the tones of browns, reds and oranges are colors of whites, blues, yellows and purples.

Spring is a time when the wildflowers bloom, and consensus is this spring's display will be among the best. It's a time for visitors to see large patches of sego lilies, the state flower, and blooming lupine, Indian paintbrush, gentian, bellflower, yarrow, gilia, desert phlox, shooting star and manzanita.

Conditions, explained Paul Henderson, chief of interpretation for the National Park Service out of Moab, "have been perfect. I don't know that a lot of people come just for the wildflowers, but I'm sure some do. Those who do are glad they came when they did.

"In another couple of weeks, depending on weather conditions, we should have a pretty spectacular display of wildflowers ... some early arrivers and some later arrivers. Wildflowers should be in bloom from mid-April to mid-May."

Ideal growth conditions for wildflowers include good moisture in the spring, winter and fall and plenty of sunshine, and this year all the requirements have been met.

How many people will visit one of Utah's parks this year — state or federal — is pure speculation at this point. The general feeling is all parks will be busier.

Visits to Arches National Park were up by more than 30,000 people last year for a final figure of more than 860,000 visitors. Visits to Canyonlands National Park were up nearly 27,000, which is significant in that it traditionally gets about half the number of visitors as Arches.

"Those totals are the highest since 1999," said Henderson. "Between 1985 and 2000, the number of visitors quadrupled. The best years were 1998 and 1999. It appears now we're in an upward growth pattern again, and I don't know what to attribute that to. It does appear, in the 10 years I've been here, that the shoulder seasons have gotten broader and broader. People are realizing that spring and fall are good times to visit."