Union Bay Natural Area is an outdoor classroom, field research laboratory, former landfill, urban oasis and home to beavers, turtles and more than 200 species of birds.

The University of Washington owns and manages the area.

In 1916, when Lake Washington was lowered nine feet, the area was a mixture of peat, marsh, mud and swamp that considered a wasteland. So, in 1926, the University of Washington, which owned the site, began leasing it to the city to be used as a garbage dump.

Five decades later when the landfill was finally closed, it was capped by a layer of clay and two feet of soil. It became known as “The Fill.”

As the soil settled, the landscape became the Union Bay Natural Area, which now boasts wetlands, woodlands, prairie and a shorebird area. It’s also become one of the premier birding sites in the state.

Location: University of Washington campus

Distance: 1 mile

Destination: Loop trail

Difficulty: Easy

Elevation gain: None

Getting there: From I-5, take exit 169 (NE 45th Street, NE 50th Street). Turn east on NE 45th Street. Go past the University of Washington and down the viaduct, staying on NE 45th Street. At the bottom of the viaduct, go left at the light, turning on Montlake Boulevard.

After passing the University Village shopping mall, turn right on Mary Gates Memorial Way, passing the UW golf course. Where the road begins to curve left, turn right into the Center for Urban Horticulture. Follow the road to the trailhead parking lot located to the right of the buildings.

The Trek: After parking in the small lot, locate the gravel path named Wahkiakum Lane. Continue to an kiosk complete with map and a brief history of the area. After getting you bearings, continue southwest upon a double-wide gravel trail.

Pass patches of blooming chickory, its bright lavender flowers a constant companion along the trail’s length.

Continue through Wahkiakum Prairie, where non-native sweet vernalgrass is found along with native camas, slender cinquefoil and Roemer’s fescue.

The area has been manipulated in the name of science. Different soil treatments have lowered nutrients and mounds have been built to create micro-habitats.

It’s a birder’s paradise, so be prepared to encounter folks with binoculars and UW students making their way to and from class.

At a “Y” intersection, continue straight. The path to the left will be the return route.

Reaching Shoveler’s Pond, read how it’s a winter favorite for migratory waterfowl. A vernal pond, it boasts water five months of the year. At one point, the pond was covered with invasive purple loosestrife, which is now controlled by the Galerucella beetle.

Passing the now waterless pond, the upper decks of Husky Stadium dominate the skyline to the southwest while towering dorms loom to the northwest.

Fruit-bearing trees, from crab apples to pears, dot the landscape. Their fruit-filled limbs hang low.

Reach an intersection just beyond a huge pile of woodchips. Straight leads to an abandoned parking lot and another entrance to the area. Proceed left.

The path now borders a large field. In the distance, the Highway 520 floating bridge can be seen spanning the choppy waters of Lake Washington.

Side trails snake off from the main path in seemingly every direction.

The trail now borders a large field. A pair of fruit trees located in the middle break up the rolling prairie.

On the right is another pond, surrounded by tall cattails and lilies. Its surface is dotted with lily pads.

Take the time to meander along the shoreline, while watching closely for any of the numerous birds that may be spotted.

On this rather blustery day, a lone great blue heron sat on a log, the wind ruffling its plumage.

Returning to the trail, bend to the east as one walks just above the thick vegetation located along the shoreline of Lake Washington.

The trail now leaves hikers completely exposed to the elements as the wind howls across the lake. Pass Central Pond, the larger of the two ponds currently filled with water, as you make your way under the massive canopy of an ancient cottonwood tree.

Pass a charred pine tree, remnants of a wildfire that scorched the area this past summer, moments before completing the loop and taking a right to return to the rig.