Utah's most popular recreation attractions are that way for various reasons, not the least of which is that they are incredibly beautiful.

Nine of the top 10 are on the national register for scenic wonders. The only one that's not is a state park — Wasatch Mountain.

Between them, they play host to nearly 10 million visitors a year.

The ruling four are Zion, Glen Canyon, a k a Lake Powell, Flaming Gorge and Bryce Canyon, then comes Wasatch followed by Arches, Grand Staircase, Capitol Reef, Cedar Breaks and Canyonlands.

It's a good bet that with the upcoming Memorial Day weekend they will be, as always at this time of year, busy. It's a good bet, too, that finding a camping spot within any of their boundary lines will be difficult if not impossible over the holiday.

Finding a parking spot or a scenic hiking trail or a place to grab a sandwich and cold drink won't be as much of a problem.

Zion took steps to ease crowding a few years back by banning vehicles and offering bus rides to visitors.

With no vehicles to contend with in the most popular area of the park, said Ron Terry, park information officer, "We've made the park more accessible to visitors. It's made it possible for people to do more things."

Reasons why Zion, with more than 2.5 million visitors each year, is Utah's No. 1 scenic attraction are as numerous as its natural wonders. It has also gained an international reputation, which draws in a lot of people from outside the United States.

There are 280 camping spots within the park. Half are by reservation and half are on a first-come, first-served basis. Typically on holiday weekends, all campsites are taken by Thursday. Those hoping to squeeze into a spot will need to arrive early and wait and hope.

Among the more popular activities in the upper section are to take the Riverside Walk (2 miles round trip), hike to Angels Landing (5 miles round trip) and hike to Emerald Pools (roughly 3 miles round trip).

Zion's satellite park, Kolob, is no less spectacular, albeit much smaller. There are no in-park camping sites available.

Lake Powell will be crowded over the holiday. And lines at the fee station could be somewhat longer this year. Park staff will be asking questions and checking boats to hopefully avoid contamination by the zebra mussel, which was discovered this past January in Lake Mead.

Here again, the advice is to arrive early.