Preservation of Lilac Way’s Rock Island continues today.

The original 5-acre Lilac Park on Highway 100 and Minnetonka Boulevard in St. Louis Park, MN was built in 1939. In 1968, roadwork split the park in two.

The south section had the beehive fireplace, which was saved and restored in a new Lilac Park.

The north section’s remaining rock garden with a pond, island and L-shaped bench became known as Monkey Island or Hidden Park. We prefer the name Rock Island.

Now hidden behind a sound wall, we’re raising awareness for continued preservation of these historic Lilac Way structures.



STAY TUNED! Details for the next Rock Island cleanup event will be posted soon. See the photo gallery of the May 4th cleanup event.

City Council Member Margaret Rog encourages you to visit Rock Island, then send her an email if you think Council should consider making a modest investment to preserve this historic area.

After surviving 80 years of Highway 100 construction, it deserves a second chance.

What is ‘Rock Island’?

This amazing rock island, AKA Monkey Island, was built in 1939 by the WPA. It has an oval pool, a 10′-long footbridge to an island and a stunning hand-built L-shaped stone bench. They are rare historical Lilac Way ‘parkitecture’.

Watch the videos for a virtual tour.

Many original 1939 Lilac Way structures remain in Rock Island park, including an oval pool with a 20′ wide island, flagstone paths, a wrap-around stone bench, stone walls and landscaping.

Directions to Rock Island.

It’s even on Google maps! It’s located behind a sound wall near Highway 100 and Minnetonka Boulevard in St. Louis Park, MN.

  • From Highway 100, go east on Minnetonka Boulevard
  • Turn left on Salem Avenue
  • Turn left on W 29th Street
  • Turn right on Toledo Avenue South
  • The park is on the west side of Toledo Avenue on the 2800 block, under the trees near the wall
You can’t see the park from the street, it is lower than street level.

Walk towards the clump of trees near sound wall. There may be a slightly worn path through the grass.

You will come up to a small set of stairs that leads you down into the park.

Key Supporters

Michael Periolat, St. Louis Park resident
Resident Michael Periolat is interested in a grassroots movement to preserve Rock Island.

Growing up just four blocks from this park, Michael never knew it existed.

After buying his own home nearby, he discovered the park and is encouraging others to step forward to support preservation of this rare 1939 Lilac Way park.

Margaret Rog, St. Louis Park City Council Member, Ward 1
Margaret Rog, SLP Council Member has
  • proposed to colleagues that they discuss a commitment of resources to this park
  • raised issue of preserving park as a potential study session topic
  • recommended encouraging project supporters to email, meet with and contact council members, to increase chances of moving it forward
  • requested community feedback re: The City of SLP making a modest investment to preserve the historic area for kids, families, seniors and others to enjoy
Diane Steen-Hinderlie, St. Louis Park resident
Diane Steen-Hinderlie and her husband John Olson have
  • volunteered to maintain this park since 2009
  • cleaned, weeded and uncovered 1939 structures
  • saved sections of 62′ stone wall from road construction
Karen Laukkonen, Restore Lilac Way, St. Louis Park resident
Karen Laukkonen, has
  • documented Rock Island since 2007
  • raised awareness for preservation through
  • created signage and displays

What the City of St. Louis Park has said about Rock Island

In 2012, the City Council reached a consensus that staff resources or money should not be spent to restore Lilac Way’s Rock Island.

We’re hoping they will review and reconsider that decision to save this park built in 1939.

The Official Minutes of a City Council Special Study Session on Nov. 19, 2012 included:

Councilmember Sue Sanger asked Ms. Diane Steen-Hinderlie if she was aware of any group that might be able to put the time or effort into preserving the Rock Garden.

Ms. Steen-Hinderlie approached the City Council and stated the Rock Garden has been neglected for a couple of decades and they would have to educate the community about the Rock Garden. She indicated the Historical Society has agreed to let them write an article for the Re-Echo regarding the Rock Garden to see what ideas people might have for preserving it.

Mayor Jacobs felt it should be left to residents to come up with a plan for preserving and relocating the Rock Garden.

A Nov. 19, 2012 discussion item stated:

A desire was expressed to preserve the Rock Garden – a water feature with a small waterfall, a circular concrete water storage area and a concrete slab to walk across the circular water area. The Rock Garden was evaluated by the City, MnDOT, Three Rivers Park District, SLP Historical Society, SLP Park Commission and some interested residents at the same time the Beehive was relocated in 2009.

The Rock Garden appears to be very deteriorated and there seems to be general agreement by all parties involved that it is not salvageable. MnDOT has indicated that if there is a desire by the City to preserve this, they will work with the City to cordon the area off and attempt to protect the garden until it can be relocated by others.

Brainstorm ideas for preservation of Lilac Way’s rare Rock Island

  • Preserve key features of original 1939 design
  • Create areas for families and community members to enjoy and appreciate the park’s history
  • Encourage support from St. Louis Park City Council members
  • Use crowdfunding and invite local businesses to donate to a non-profit to fund preservation, reducing support from the City of St. Louis Park
  • Launch ‘pop-up events’ to raise awareness of this park — music concerts, outdoor activities, family play days, information classes, etc.
  • Rally the community behind preservation, similar to the movement to restore Graeser Park
  • Add stone picnic tables, a grill, and a fireplace – all created new in keeping with the spirit of landscape architect Arthur Nichols
  • Convert original waterfall to a pondless design
  • Create a ‘Rock Island’ garden club that maintains the park periodically
  • Scatter the field area with wildflowers
  • Promote new consideration for preservation now that the entrance ramp, exit ramp, and Highway 100 are no longer a barrier
  • Bring in experienced local stonework company to create family-friendly structures
  • Encourage support from St. Louis Park City Council members

Rock Island’s large wraparound bench was handcrafted by unemployed stonemasons in 1939 from limestone quarried from the Minnesota River by the Mendota Bridge.

Comments from the City of St. Louis Park
  • MnDOT still owns the property
  • Sean Walther, AICP Planning and Zoning Supervisor of SLP, has indicated that the city may like to acquire and control the property
  • MnDOT typically does not release any land until a road project is 100% complete, there is still landscaping that is supposed to occur in the Hwy 100 corridor in 2018
  • Could take months or years after project is completed to work its way through MnDOT’s process; occasionally, MnDOT will expedite the process, but that is relatively rare
Diane Steen-Hinderlie status report to St. Louis Park Historical Society on August 9, 2016:
  • Cleanups on Earth Day and a quarterly scheduled cleanup
  • Visited by Erin Berg, representing Preservation Alliance of Minnesota (PAM)
    • Sponsored by Birchwood Neighborhood Association
    • Erin suggested organizations that could help with cleanups, including Conservation Corp.
  • Site could be re-evaluated as
    • candidate for National Register of Historic Places
    • a local historic site as designated by the MN Historical Society
    • or a “Place of Value” as designated by PAM
  • Site has unique “sawtooth rocks,” a signature feature of landscape architect Arthur Nichols, who designed 7 Lilac Way roadside parks
  • Fencing is gone from site, working with MnDOT to preserve or replace it to prevent people from taking souvenirs
  • Read meeting minutes
Rock Island Park key dates
  • In 1968 the original Lilac Park was split in two by a highway on-ramp, and Lilac Park activities were reduced
    • the park could no longer be accessed from the highway
    • the grade from Toledo Ave. was steep and difficult to walk down
    • the rock garden that was north of the beehive fireplace and picnic area was cut off from the rest of the park
  • In 2008, the 1939 beehive fireplace and picnic tables were saved, and moved to a restored Lilac Way park on Highways 100 and 7, which was renamed Lilac Park
  • In July 2009, a crew mistakenly cut down all the trees that hid this park, making it visible to traffic on Highway 100
  • In 2017, Rock Island Park was again hidden, when a new sound wall was installed along Highway 100
Historical info
  • One of seven original Lilac Way parks
  • Designed by Arthur Nichols, Landscape Architect
  • Built by Works Progress Administration (WPA) as part of one of Minnesota’s largest federal relief projects, 1934-1941
  • Hand-built by unemployed men during Great Depression
  • Significant in the state’s history of transportation
  • Determined ineligible for National Register status

What did the WPA build in the Rock Island section of the original Lilac Park on Minnetonka Boulevard in 1939?

Rock Island, May 2018. 10′-long footbridge.
Limestone walkway at the original Lilac Park on Highway 100 and Minnetonka Boulevard
Rock Island in Lilac Park (original), Mtka. Blvd., 2007. Pool, curved paths, 10'-long footbridge.
Oval pool, island and path, Rock Island Park (also known as Hidden Park-Monkey Island)
  • Near north end of site
  • Elaborate rock garden is hidden by sound wall
  • Built of tan, mortared limestone rubble
  • Oval-shaped pool lined with stones and encircled by a flagstone path
  • In the center is an island (about 18-20′ in diameter) ringed with tan limestone rubble
  • A willow tree grew out of island
  • A 10′-long footbridge, comprised of two slabs of limestone on limestone piers, leads to island from east side
  • South end of pool had a waterfall made of mortared rocks
  • Curving limestone steps climbing the back of the waterfall
  • Curving paths are paved with flagstone
  • Lower path encircling pool is edged with low, stone retaining walls
  • Another path, which runs at a higher elevation along the eastern side of the garden, is lined with stones that are set so the triangular ends point upward
  • Was separated from the rest of the park circa 1968 by the exit ramp from northbound Highway 100 to Minnetonka Boulevard which cuts through the park near north end
  • Remains today, needs preservation
Rock Island, May 2018. L-shaped stone bench.
Bench, Rock Island Park (also known as Hidden Park-Monkey Island)
  • Small niche east of waterfall contains an L-shaped stone bench with a 2′-tall backrest
  • Remains today, needs preservation
Rock Island, 1 of 2 sets of stone steps.
Rock Island, May 2018. 1 of 2 sets of stone steps.
Steps, Rock Island Park (also known as Hidden Park-Monkey Island)
  • Two sets of 5-6 stone steps lead down into rock garden from southeast and southwest corners
  • Side railings of small mortared rocks
  • Remains today, needs preservation
Rock Island, May 2018. Low stone wall, 18" thick.
Limestone wall at the original Lilac Park on Highway 100 and Minnetonka Boulevard
Lilac Park (original), Mtka. Blvd., 2007. 162'-ft long curved wall, N of park.
Low stone wall
  • Not part of original Rock Island area, was formerly located in south picnic area where 29th Street meets Toledo Avenue
  • Was dismantled and moved to Rock Island area after picnic area of park was removed for road construction
  • 18″ thick
  • Built of tan, random ashlar, rock faced limestone
  • 62′ long, curved shape, runs at angle along crest of hill
  • Wall was anchored with stone piers at ends and at two pedestrian openings
  • Was originally longer and lined with a short, curved pull-off drive (from Toledo Avenue) that probably formed a parking area
  • Several feet of stonework from each end of wall were removed, and curved drive eliminated circa 1968 when an exit ramp from northbound Highway 100 was built through the site
  • Remains today, needs preservation

Read MnDOT’s 1964 Wayside Rest Area Inventory (JPG) for the original Lilac Park on Minnetonka Boulevard.

Read MnDOT’s 1997 Historic Roadside Development Structures Inventories (PDF) for the original Lilac Park on Minnetonka Boulevard.