The short version
The McDowell Sonoran Preserve is more than 30,500 acres of desert and mountain land that the City of Scottsdale owns and has promised never to develop, with more than 230 miles of trail. It is the city’s biggest land-use decision, and the council did not make it alone. Voters did, repeatedly, and they have kept the final word ever since.
The pattern repeats across three decades. Citizens organized first, as the McDowell Sonoran Land Trust in 1991. The council adopted a resolution establishing the Preserve on October 3, 1994. Then voters paid for it, approving a 0.2% sales tax on May 23, 1995 and an extra 0.15% on May 18, 2004, each for 30 years. They also approved spending that money inside a much wider planned boundary in 1998, and in 2018 they wrote its protection into the city charter.
Who does what
The council owns the decisions on paper: it adopts Preserve ordinances, budgets the tax money and approves land purchases. In practice it works inside limits the voters set, on how the money can be spent and what can happen on the land.
The McDowell Sonoran Preserve Commission, seven residents appointed by the council, advises on acquisition, funding, master planning and trails. Most Preserve questions surface there first.
The McDowell Sonoran Conservancy, the Land Trust under the name it took in 2005, is a nonprofit partner. Its volunteer stewards, trained since 1998, patrol trails, lead hikes and do field research; the city treats the Conservancy as its formal partner in caring for the land.
Voters hold the reserve power. Selling Preserve land, removing its designation, building on it or spending its dedicated money on something else all require their approval. The ballot measures guide explains how those votes get on the ballot.
How the land was bought
The Preserve was bought, not zoned. Zoning can be changed by any future council; land the city owns and has pledged in its charter is much harder to lose. So the taxes paid for real purchases at market prices from ranch owners, failed subdivisions and the state.
Much of the McDowells and the northern desert was State Trust land, held by the Arizona State Land Department to earn money for public schools. Under the state constitution, trust land is sold at public auction to the highest bidder, at no less than its appraised value. The state’s Arizona Preserve Initiative let the city ask for parcels to be classified as suitable for conservation, but Scottsdale still had to win them at auction like any other buyer. The 2004 bond authority, up to $500 million repaid from the tax, let the city buy ahead of rising prices rather than wait for revenue to pile up.
The purchases began under Mayor Sam Kathryn Campana in the late 1990s and continued through Mary Manross’s years and beyond. The Gateway Trailhead opened in 2009 and Brown’s Ranch in 2013, both on Preserve land. Today, with buying largely done, the argument has shifted to upkeep, rangers and trails, which is what the 2024 tax is for; the budget guide shows where it fits in the city’s sales tax.
A boundary set at the ballot box
The original recommended study boundary, used from 1995 to 1998, covered about 16,460 acres, mostly the mountains themselves. In August 1998 the council adopted a resolution adding about 19,940 acres of northern desert, including State Trust land judged suitable for conservation, and on November 3, 1998 voters approved spending Preserve tax money inside the larger line. The planned Preserve became about 36,400 acres, roughly a third of the city. The same November 1998 ballot carried a charter question on disposing of Preserve land, and the charter today bars the city from giving up Preserve land or removing its designation without a public vote. The volunteers around Jane Rau, whose group had proposed setting aside about a third of the city, had their goal written into law.
The Desert Discovery Center and Prop 420
The test of who was in charge came over the Desert Discovery Center, an interpretive attraction the city spent years planning for the Gateway Trailhead. Supporters saw a way to teach visitors the desert they were already hiking. Opponents saw buildings, parking and admission fees on land voters had taxed themselves to keep natural. A scaled-down version was unveiled in 2017, and by year’s end the council had paused it while opponents gathered signatures.
The result was Prop 420, a charter amendment proposed by initiative petition. It added two sections to the charter: one prohibiting alteration of the natural state of Preserve land, and one limiting the use of Preserve funds, each unless voters approve. Opponents argued it was overly broad and would complicate trail and trailhead management. On November 6, 2018, it passed with about 71%, and the Discovery Center was finished.
After the land-buying
The 1995 tax expired at the end of June 2025. The council referred Prop 490 to the November 5, 2024 ballot: a new 0.15% tax for 30 years for city parks and recreation facilities, Preserve maintenance and protection, and related police and fire. Its wording drew a court challenge, and an appeals court ruled that the city had not explained well enough what a no vote meant, so the council rewrote the ballot language before the election. Voters approved it, and the new rate took effect July 1, 2025, bringing the city’s sales tax rate to 1.70%. By the city’s own breakdown, almost 9% of that tax now goes to buying Preserve land (the 2004 tax, which runs 30 years) and almost 9% to parks and recreation. Every future turn in the Preserve’s story, as with each one since 1995, is likely to go through the voters.