
The Purple Martin Water Resource area is a hidden gem that offers clean water and outdoor recreation opportunities. Conveniently located just two miles west of Walnut Woods State Park in West Des Moines, this picturesque destination is a must-visit.
The centerpiece is Purple Martin Lake, a haven for outdoor enthusiasts. So, if you enjoy fishing, paddling, hiking, or bird-watching, don’t miss the chance to explore Purple Martin Lake, just a stone’s throw away from Walnut Woods State Park.
A Brief History of Purple Martin Water Resource Area
Purple Martin Lake used to be a rock and sand quarry. Des Moines Water Works now owns the area and uses it as a source of clean drinking water for half a million people.
In a joint project among Des Moines Water Works, the Iowa DNR, the City of West Des Moines, and Friends of Walnut Woods, Purple Martin Lakes opened as a public outdoor recreation area in 2017.
Things to do at Purple Martin Lake
Watch the Purple Martins!
Purple Martins are the largest among the swallow bird species. The species rely primarily on humans for housing, and their population is dwindling. Learn more about this bird at the Water Resource Area! And you’re sure to enjoy the activity around several Purple Martin birdhouses. The birds’ blue shimmering feathers and aerial feats will keep you entertained! The best viewing is from late April through mid-August.

Hike the Trail
Tree Swallow Trail is a 1.7-mile trail surrounding the west, south, and east shores of Purple Martin Lake. Hikers of all levels can navigate this flat, mowed trail through the native grasses and wildflowers. And the path is excellent for snowshoeing and cross-country skiing in the winter.
Trail Note: Keep in mind this is not a loop trail! The trail does not connect the northeast and northwest corners of the lake.
Go Fishing
Fish from the shore or your boat! The clear waters of the 87-acre lake are perfect for fishing or just enjoying the water. You’ll catch mainly carp, though the lake was stocked with bass in 2019.
Paddle the Lake
Enjoy the pristine waters and beautiful views while paddling around Purple Martin Lake! Bring your own non-motorized boat, and put it in at the boat ramp on the lake’s south side, near the parking area.
Purple Martin Lake Map

Map credit: Iowa DNR
Download the Walnut Woods State Park Map and Flyer for a larger map.
Other Things To Do Nearby
Just two miles east of Purple Martin Lake, go to Walnut Woods State Park! There, you’ll find campsites and access to the Raccoon River. Enjoy hiking, picnicking, and fishing under the shade of mature Black Walnuts in this 260-acre state park.
Brown’s Woods Forest Preserve is four miles east of Purple Martin Lake, past Walnut Woods State Park. Browns Woods has over 4 miles of hiking trails through mature woodlands and small streams.
Raccoon River Park is across the river off Grand Avenue in West Des Moines. This city park offers a wide array of outdoor recreation for all ages. Visit the public beach, large playground, ice skating rink, or rent a boat at the new boathouse!
If you’re looking for an excellent paved trail, the Great Western Trail is a few miles east of Purple Martin Lake. The 16.5-mile trail runs from Des Moines south through Cumming, ending at Martensdale. Great Western Trail is popular among cyclists.
If you want a bite to eat, head north on I-35 to the Mills Civic Parkway exit. You’ll find shopping and dining options west of the exit, including Jordan Creek Town Center.
Visit Purple Martin Water Resource Area Today!
Purple Martin Water Resource Area is near the 10900 block of Army Post Road in West Des Moines. From I-35, take the Highway 5 Bypass (Exit 68). Next, take the SE 35th St/Walnut Woods exit off the Bypass (Exit 102). Head north on SE 35th Street, and turn left (west) onto Army Post Road. Follow Army Post Road to the dead end.
Park hours are 6:00 am to 10:30 pm.
Free parking is available in a gravel/dirt parking lot.