Trails: Ice Age and East Boundary Trails
Hike Location: Robert O. Cook Memorial ArboretumGeographic Location: northwest side of Janesville, WI (42.71520, -89.05369)Length: 3.6 milesDifficulty: 5/10 (Moderate)Last Hiked: May 2019Overview: A lollipop loop with a mixture of creekside and ridgetop hiking passing an historic log cabin.Trail Information: Route Map:
Directions to the trailhead: Near Janesville, take I-90 to US 14 (exit 171B). Exit and go west on US 14. Drive US 14 west 4.5 miles to Washington Street. Turn left on Washington St. and drive south 1.3 miles to the signed trailhead parking for the Ice Age Trail on the left. This gravel parking lot is reached just after passing under a railroad bridge.
The hike: Winding for nearly 1200 miles around central and southern Wisconsin, the Ice Age Trail is one of the nation’s premier long-distance backpacking trails. The trail is the brainchild of Milwaukee attorney and conservationist Ray Zillmer, and its route roughly traces the furthest advance of glaciers during the most recent ice age, hence the trail’s name. With 600 miles of trail constructed, the Ice Age Trail is about half complete, and work continues to reroute the remaining segments off of roads and onto dedicated trails. Like most long-distance backpacking trails, the Ice Age Trail is divided into segments. The Ice Age Trail’s Arbor Ridge Segment is featured here. The relatively gentle Arbor Ridge Segment passes through the Robert O. Cook Memorial Arboretum, which is owned by the City of Janesville and maintained by the Janesville Public School District. By using some of the arboretum’s trails, you can form a lollipop loop that gives a taste of Ice Age Trail hiking without forcing you to retrace your steps for the entire distance. Such is the route described here.

Ice Age Trail trailhead

The Ice Age Trail’s trailhead on Washington St. serves both the Arbor Ridge Segment to the west and the Devil’s Staircase Segment to the east. The Devil’s Staircase Segment quickly leads to its namesake rock formation along the Rock River, and it is worth exploring if you have more time than I did. To find the Arbor Ridge Segment, walk northwest across Washington St. to find the wooden post bearing the official Ice Age Trail shield that marks the start of the segment.

Start of the Arbor Ridge Segment

The mowed grass trail heads northwest with Northridge Drive on the left and a railroad track on the right. After briefly following the shoulder of Northridge Drive, the trail curves right to head into a narrow strip of woods. The Ice Age Trail is marked with yellow rectangular paint blazes, and this segment of the trail is very well-marked and well-maintained. My thanks go to the Ice Age Trail Alliance for building and maintaining such a high-quality track. Soon the trail surface changes from mowed grass to single-track dirt, and the railroad track is replaced by a pleasant flowing stream called Marsh Creek that features some nice but small cascades. After some gentle undulations, at 0.8 miles you enter the arboretum and approach a meadow. This meadow contains the trail intersection that forms the loop portion of this hike. The signed East Boundary Trail going left will be our return route. This hike continues straight to remain on the Ice Age Trail, thus hiking the loop counterclockwise.

Marsh Creek

On the other side of the meadow, you reach a nice area with benches overlooking a scenic ripple in Marsh Creek. Next the trail curves left and heads away from the creek by climbing up a wide ravine on a gradual to moderate grade. Overall, the trail gains just over 150 vertical feet in 0.4 miles. Metal and wood interpretive signs point out common plants in the forest, which include cottonwood and oak trees. The trees were just starting to put out leaves on my visit in mid-May, and some redbuds in bloom brightened my path.

Hiking the Ice Age Trail

Several trails go up this ravine, but you can simplify your route-finding task by just following the Ice Age Trail’s yellow blazes. As you approach the top of the hill, the arboretum’s amphitheater comes into view through the trees on the right, and the trail passes through an outdoor classroom designed for use by elementary school students. Some blue aluminum circles nailed to trees mark a short loop that you could add-on if you wanted to extend your hike by a few tenths of a mile.Just shy of 2 miles, you intersect an asphalt trail as you approach the north end of the arboretum. We will eventually turn left here, but first look to the right to see a piece of Wisconsin history: the Hornby Log Cabin. Built in the 1850’s by James Hornby, the cabin was purchased by the Janesville Public School District and moved from its original site in Liberty Pole, WI (a small town in southwest Wisconsin northeast of Prairie du Chien) to here in 2001. The cabin represents a typical Wisconsin homestead during the period, and some interpretive signs give information about the cabin’s history and the people who built it.

Hornby Log Cabin

The asphalt trail continuing west past the cabin leads to the arboretum parking lot and the end of the Ice Age Trail’s Arbor Ridge Segment. To continue our loop, leave the Ice Age Trail by heading east on the asphalt trail. Less than 500 feet later, the asphalt trail ends at a gated intersection with Arbor Ridge Way, a residential street. Turn left and walk downhill a few hundred feet on Arbor Ridge Way to find the start of the East Boundary Trail, which is marked by a sign and another brown metal gate.

Start of the East Boundary Trail

For its entire 0.7 mile distance the East Boundary Trail follows under a power line as it heads north in a straight line. Thus, the East Boundary Trail does not make for the most scenic hiking. On the bright side, this route reduces the retracing of steps, some nice views to the north appear down the power line clearing, and I saw many songbirds including goldfinches in the prairie under the power lines.

Looking down the East Boundary Trail

After a steep descent, you close the loop at 2.8 miles. Turn right and retrace your steps along the Ice Age Trail 0.8 miles to the Washington St. trailhead to complete the hike. If you have some more time, check out the Devil’s Staircase Segment of the Ice Age Trail, which starts from this same trailhead but goes the opposite direction from this hike.