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Monarch Highway

What is the Monarch Highway, and how did it come to be?

Monarch Highway Map, base layer courtesy of the US Fish and Wildlife Service, modifications by the Monarch Joint Venture.
Monarch Highway Map, base layer courtesy of the US Fish and Wildlife Service, modifications by the Monarch Joint Venture.

The “Monarch Highway” is a symbolic migration corridor that follows Interstate-35 (I-35) from Laredo, Texas, to Duluth, Minnesota, aligning with the central flyway of the eastern migratory population of the monarch butterfly. The symbolic highway is a partnership effort bringing people together to catalyze conservation actions throughout the central flyway. However, in order to bring back the monarchs, conservation efforts are needed from everyone throughout the entire monarch range. The map below shows monarch migration routes, the approximate route of I-35, and the "Monarch Highway" states.

Who is involved with the Monarch Highway?

I-35 was identified as the “Monarch Highway” by the State Departments of Transportation in the central flyway, including Minnesota, Iowa, Missouri, Kansas, Oklahoma, and Texas. However, the effort to conserve monarch butterfly habitat in this corridor extends beyond the roadsides managed by these DOTs. The conservation activities of the agencies, companies, non-profits, and individuals who own and manage land within the corridor can contribute to a network of connected habitat across the landscape for monarchs.

What can I do to help?

The most important action you can take to benefit monarchs and other pollinators is to create or improve habitat that contains native milkweed and wildflowers and develop a long-term maintenance plan for those habitats. Contribute to the Monarch Highway by working with partners to create habitat in your backyard, in marginal weedy areas, at community gardens, on public lands, along utility or transportation rights of way, at schools, on corporate campuses, and just about anywhere else you can think of. For more information about creating habitat for monarchs, visit

Your feedback to state and local land management agencies, including DOTs, is encouraged to help support their efforts to expand monarch habitat conservation at roadsides, rest areas, and other public lands. Your vocal support of these efforts is critical to their work to improve and maintain areas for pollinators on public lands.

The handout below is available for download and printing. You are welcome to download it to learn more or print it to distribute in your monarch conservation outreach efforts.  Click here to download the below handout.

What are the state DOTs doing to contribute to monarch conservation?

Both within and outside of the “Monarch Highway” states, state Departments of Transportation are working on roadsides, rest areas, and surrounding habitat areas to conserve monarchs. To find out more about the efforts happening in your state or region, see the links below. This may not be a comprehensive list of all the work underway. If you are aware of DOT or roadside conservation initiatives not represented here, please contact us!

Monarch Highway States


In Iowa, state law prohibits mowing roadside vegetation or in medians on interstates, primary highways, and secondary roads prior to July 15. The Iowa DOT administers the Living Roadway Trust Fund, a grant program for integrated roadside vegetation management activities throughout the state – to create “safe and effective habitat for wildlife which can coexist with highways." Iowa DOT is a committed member of the CCAA for Rights-of-Way (see Other Resources and Information below).


For the past 15 years the Kansas DOT has been planting and protecting pollinator habitat by introducing a wide variety of native wildflowers to their standard seed mixes. KDOT also revised their mowing policy limiting the frequency and timing of mowing to allow native wildflowers and grasses to set seed and spot spraying of herbicides rather than broad application of chemicals. In 2016 KDOT joined the Monarch Highway to further promote and protect pollinator habitat along the I-35 corridor. For more information on KDOT’s pollinator efforts visit their website at or contact Melissa Davidson, KDOT Bureau of Right of Way, Roadside Vegetation Management, 785-296-0853.


The Minnesota Department of Transportation (MnDOT) actively maintains, restores and constructs roadside habitats for pollinators and other wildlife using a variety of techniques – including prescribed fire. MnDOT is working to promote pollinator habitat on roadsides, rest areas and other lands it manages, and is funding and/or participating on several projects focused on furthering our understanding roadside use by pollinators. Find more information about MnDOT's pollinator efforts online or contact Tina Markeson, MnDOT Office of Environmental Stewardship, Roadside Vegetation Management Unit Supervisor, 651-366-3619.


The Saint Louis Zoo received an anonymous donation of $100,000 to begin planting the I-35 Monarch Highway in Missouri. Contracting with DJM Ecological Services and working with MODOT, work began identifying locations and starting work. In 2021 three sites were identified to begin. They are the Eagleville Welcome Center and two further locations, including a, weigh station and rest area. (Attached are images and acreage). Sites were sprayed at the end of 2021, and the weigh station and rest areas were seeded in 2022. The Welcome Center was cut and sprayed to remove invasive plants and trees. Next phase with start in 2023, with two interchanges south of these areas being sprayed and seeded. Acreage to be determined.


The Oklahoma Department of Transportation (ODOT) is working to support the native vegetative habitats for the Monarch butterfly and other pollinator species, which grow naturally within our right of ways. ODOT’s efforts include decreased mowing practices during critical Monarch migration seasons, partnering with other pollinator habitat conservation organizations and planting Monarch specific, pollinator friendly gardens. More information can be found by contacting Vonceil Harmon, ODOT Natural Resources Program, (405) 249-5130.


TxDOT pollinator conservation actions are summarized here. TxDOT is partnering with state DNR to conserve the monarch butterfly, restricts mowing to twice a year (after spring bloom season, and again after fall blooms), uses IVM to protect wildflower lifecycle, does not broadcast herbicide, employs district vegetation managers who promote beneficial habitat that is appropriate to road type, educates adjacent landowners about the economic benefits of vegetation diversity, plants monarch gardens at rest areas. TxDOT’s wildflower program is a tourist attraction. Also notes extensive partnerships (More information here: Texas Monarch and Native Pollinator Conservation Plan – p. 26-30).

Additional State DOT Initiatives


The Alabama DOT has create wildflower plots on their lands. Visit the ALDOT website to get in touch.


The Arizona DOT avoids grass-only seed mixes and incorporates wildflowers into their native-only seed mixes. They are a committed member of the CCAA for Rights-of-Way (see Other Resources and Information below). Visit the ADOT website for more information.


Colorado has designated 183 miles of Highway 76 “Colorado Pollinator Highway.” This is part of CDOT’s larger effort to restore pollinator habitat by improving mowing practices, spot spraying noxious weeds, and using bio-controls to control weeds in roadside (article). CDOT is piloting new approaches to funding and operationalizing plantings for pollinators. More information here.


This state law in CT permits the DOT to create pollinator habitat by partnering with other organizations and using state funds. It also restricts the use of neonicotinoids. View the law here.


Delaware DOT is a committed member of the CCAA for Rights-of-Way (see Other Resources and Information below). They also reduced mowing outside safety strip on SR 1, pollinator test plots on I-95 and in the medians elsewhere (article), and installed a 43-acre pollinator mitigation site outside Middletown (poster).


Georgia DOT s a committed member of the CCAA for Rights-of-Way (see Other Resources and Information below). They have also established wildflower plantings, partnered with Ray to disseminate pollinator seed packets and created a 5,000 sq. ft. pollinator garden at a Visitor Center on I-85 (article).


In Illinois, a new mowing policy restricts mowing to a single pass (15’) along all roadsides and limits mowing outside this area to the fall. Additionally, in 2018 medians will only be mowed one pass – and beyond that only outside the restriction dates. Research suggests that there is now 80,000 acres of more habitat and the density of milkweed stems has increased 3000% (Draft Mid-America Monarch Conservation Strategy). The state budget line item for Pollinator Habitat Preservation and Restoration commits $500,000 annually (Draft Mid-America Monarch Conservation Strategy). IDOT is a committed member of the CCAA for Rights-of-Way (see Other Resources and Information below).


LDOT has created native micro-prairies for pollinators at new rest stops. See this article for more information.


The MDOT SHA Pollinator Habitat Plan requires SHA to designate certain sites as pollinator habitat that must be managed appropriately (without neonicotinoids or other pesticides that are toxic to bees). State law requires the State Highway Administration, the state DNR and Maryland Environmental Service to each establish a pollinator habitat plan.


Mississippi State University has partnered with the DOT and others to create pollinator habitat in roadsides – e.g., along 22-mile corridor on US 82 between Carrollton and Kilmichael (article, article).


NDOT’s activities include: seed mixes include 10-20% native wildflowers (by weight), funded research project with Univ. of Nebraska to explore the value of wildflower islands and their effect on pollinating species, revised mowing policies to minimize interference with pollinator life cycle, participates in state pollinator efforts, involved with state DNR’s “Nebraska’s Cowboy Trail.” View their website for more information.

North Carolina

NCDOT has partnered with NC Dept of Agriculture to extend NCDOT’s Wildflower Program by planting for pollinators along right-of-way, and together they have received corporate sponsorship to increase the impact of pollinator plantings along roadsides (article).

North Dakota

ND DOT existing pollinator practices include: Highway 1804 and I-94 incorporated pollinator species into seed mix; included pollinator species in seed mix for Crystal Springs Rest Area; added pollinator species to upland seed mixes for future mitigation sites. Future goals include changes to the mowing policy to facilitate pollinator habitat enhancement, pollinator plantings as rest areas, and prioritizing roadside vegetation management to expand natural vegetation (Source: North Dakota Monarch Butterfly and Native Pollinator Strategy).


ODOT has implemented Monarch Joint Venture’s mowing guidance. All counties are encouraged to stop mowing for maintenance or visibility May1-June 30 and then again July 15-October 15. State will continue to maintain a 30’ safety zone from the pavement’s edge % (Draft Mid-America Monarch Conservation Strategy). The Ohio Statewide Roadside Pollinator Habitat Program Restoration Guidelines and Best Management Practices developed guidance document to help with site selection, plant selection, seed mixes, preparation, planting and management for pollinator habitat along roadside. ODOT is a committed member of the CCAA for Rights-of-Way (see Other Resources and Information below). Contact Vonceil Harmon at 405-249-5130 or for more information.


TDOT Pollinator Habitat Program includes: (1) Best Management Practices (BMPs) through the use of Integrated Roadside Vegetative Management (IRVM), (2) modifying mowing schedules to be compatible with pollinator life cycles, (3) utilizing swath mowing to reduce costs and increase habitat, (4) pollinator plantings are included in new construction/rehab projects, (5) establishing pollinator meadows at Welcome Centers/Rest Stops, (6) developing pilot projects in each region, (7) creating informational signage.


In 2014, VDOT developed and implemented a pollinator habitat program to create areas planted with nectar plants and other pollinator species. Program goals: (1) habitat enhancement, (2) maintenance cost reduction, and (3) use of Integrated Vegetation Management (IVM) to increase E&S control, reduce stormwater runoff, reduce pesticide use and increase habitat/aesthetic values.


WSDOT’s Pollinator Program: (1) preserving native habitat wherever possible, (2) managing roadsides for natural succession, (3) areas beyond safety zone will only be mowed as part of multiyear strategy, (4) partnering with others to promote pollinator health, (5) incorporating pollinator habitat into mitigation and stream restoration sites, (6) creating pollinator plots at rest areas, (7) implementing selective herbicide use policy, (8) selecting roadside plant species that are long-lived, native and that can outcompete noxious weeds (to facilitate less invasive management regimes), (8) incorporating diversity to the greatest extent feasible into landscape designs, (8) developed maintenance guidance to protect pollinator species and their habitat. Future activities: increasing awareness of pollinator importance, conducting habitat preservation/restoration, updating IVM annually, finding grant opportunities, monitoring the effectiveness of pollinator seed mixes (fact sheet).


The Wisconsin DOT is a committed member of the CCAA for Rights-of-Way (see Other Resources and Information below). The Wisconsin Pollinator Protection Plan provides BMPs for establishing pollinator habitat and specific guidance for maintaining roadside for pollinators (p. 7) – e.g., salt tolerant planting near road edge, staggered/restricted mowing regimes, fast green up time for erosion control, maintaining safety zones, collaboration/communication to ensure long-term management success. WisDOT began planting native grasses and forbs along roadsides in the 1970s and has increased efforts in recent years.