Arizona Advances Wildlife Safety with the Willard Springs Overpass

Arizona’s Department of Transportation (ADOT) and the Arizona Game and Fish Department are constructing a 100-foot-wide concrete overpass on Interstate 17, 12 miles south of Flagstaff. The structure will span all four lanes east-to-west, feature tall parapets, eight miles of fencing, native-vegetation plantings, escape ramps, and guiding structures to funnel wildlife onto the crossing. Construction is ongoing, with a winter shutdown pause, and the state projects completion in fall 2026.

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The state records an average of 1,270 wildlife-vehicle collisions annually, and more than half of the incidents on the I-17 stretch targeted for the overpass occurred in the past four years. Arizona currently operates 26 dedicated highway wildlife crossings, supplemented by a network of underpasses and canal corridors. Existing structures include 13 elk- and deer-underpasses on State Route 260, three overpasses and two underpasses for desert bighorn sheep on U.S. Highway 93, one overpass and five underpasses on Interstate 11, and one overpass plus one underpass for the Sonoran desert ecosystem on State Route 77.

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The 2027 fiscal state budget allocated a recurring annual appropriation of $700,000 for wildlife-crossing planning and construction. The Willard Springs project’s total cost is $15.8 million, jointly funded by ADOT and the Game and Fish Department. After a seasonal construction pause, crews resumed work in September 2025 and anticipate finishing the overpass by fall 2026.

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• Average annual wildlife-vehicle collisions in Arizona: 1,270.

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• Collisions on the targeted I-17 segment (last four years): >50 % involved wildlife.

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• Statewide wildlife corridors have been credited with an average 90 % reduction in wildlife-related accidents.

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• Existing dedicated crossings: 26 overpasses/underpasses, plus additional canal pathways.

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Researchers will re-collar elk and deploy motion-activated cameras to assess usage after the overpass opens. The location was chosen based on radio-collared elk movement data, tracking migration, foraging, and mating patterns, according to Arizona Public Radio. The goal is to lower collisions involving elk, deer, and other large mammals while reconnecting fragmented habitats.

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ADOT’s video release highlighted the installation of tall fencing to act as a funnel for animals. The Game and Fish Department emphasized that site selection relied on detailed telemetry research. State officials noted that the dedicated $700,000 annual appropriation reflects a long-term commitment to wildlife safety and habitat connectivity.

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• “Crews are right now installing miles of tall fencing on either side of the overpass,” — Arizona Department of Transportation, spokesperson, September 2025 video

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• “This will act as a funnel to guide [animals] through the crossing.” — Arizona Department of Transportation, spokesperson, September 2025 video

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• “By investing in dedicated funding for wildlife crossings, the state can help reduce dangerous and costly collisions while reconnecting animal habitat across the landscape,” — Andres Esparza, senior conservation analyst, Pew

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• “These projects are proven to deliver lasting benefits for drivers, wildlife, and local communities.” — Andres Esparza, senior conservation analyst, Pew

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The cited 90 % accident reduction reflects performance across Arizona’s entire wildlife-crossing network; no post-completion data exist yet for the Willard Springs overpass. Consequently, the specific impact of this new structure remains to be measured.

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The overpass is slated for opening in fall 2026, followed by a monitoring phase using recollared elk and camera footage. Additional overpasses are planned at Kachina Village (I-17) and west of Parks (I-40), expanding the state’s wildlife-crossing portfolio. Continued annual funding will support maintenance, monitoring, and future corridor projects.

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