WATERLOO - The definition of a trail varies, depending on whether you're talking to a hiker, biker or kayaker.

According to Vern Fish, director of the Black Hawk County Conservation Board, the best trails fall into all three categories - paved, unpaved and water.

Over Memorial Day weekend, Fish paddled the Wapsipinicon River Trail. He said he likes to hike the loop at Hickory Hills, where he can climb 100 feet above the lake, and loves bicycling the stretch of the Cedar Valley Nature Trail between Hartman Reserve Nature Center and George Wyth State Park.

"It's just a beautiful bike ride," Fish gushed. "I don't think there's anything better than that six-mile loop."

Fish's love for the trails that crisscross the Cedar Valley is shared among many outdoor enthusiasts, many of whom could be out this Saturday during the 17th annual National Trails Day.

While there are no official events planned in Northeast Iowa, Heather Sable, trail programs manager at the American Hiking Society, said the day can be celebrated by going out on a new or favorite trail and helping to maintain and clean up those trails.

"National Trails Day serves as that gateway so some people can be introduced to the outdoors," Sable said. "It instills that love for the outdoors, and then hopefully they will want to give back."

Kim Burger, director of the Cedar Falls Visitors and Tourism Bureau, does a lot of biking on the trail between Hartman Reserve and George Wyth and said it was a popular segment to bike.

"It's so beautiful, right alongside the river, and I always see people I know," Burger said.

Tom and Julia Romanin enjoy biking the Hartman-to-George-Wyth loop, but they really like the 10-mile loop that goes out to Big Woods Lake and Black Hawk Park in Cedar Falls.

"That's probably the favorite," Tom Romanin said. "It has the most scenery and variety on the trails."

For hiking, Dave Sunne, a park ranger at Backbone State Park in Dundee, said he loves the Backbone Trail - named because it is shaped like a spine.

"It starts out real narrow, real scenic. It's 80 to 100 feet straight down on both sides of you," Sunne said. "There's unique vegetation up there … and a lot of other endangered species."

Hartman Reserve director Ed Gruenwald admits bias to loving the 1.5-mile upland hike along the Hartman bluff.

"There's always something new going on over there, and different kinds of plants that don't grow anywhere else," he said.

Peter Komendowski, who sits on the boards of many conservation groups, including the Cedar Trails Partnership, said he likes the wilderness hike along the Katowski Greenbelt from Cedar Falls to Hudson.

But for paddling purposes, Komendowski said it doesn't get better than the canoe portage trail that includes four lakes in George Wyth, two lakes in Hartman Reserve and the Cedar River.

"I'm looking at two real gems that emulate a real wilderness experience," Komendowski said. "This is so unique. You don't find it everywhere ."