Drive southeast of Tucson, past Houghton Road and out toward the Rincon Mountains, and you reach Vail — an unincorporated community that has quietly become one of the metro's fastest-growing residential corridors. Most of that growth is landing inside one project: Rocking K, a master-planned community of roughly 5,000 acres at the base of the Rincons and next to Saguaro National Park, about 25 miles from downtown Tucson. Per the community and its HOA, Rocking K already has close to 700 occupied homes and around 2,000 homesites sold, with eight national builders working lots. The latest news gives the corridor a fresh marker: per a June 2026 announcement, Mattamy Homes closed on its newest neighborhood there, Alamar, on June 10, 2026. Here is the June 26, 2026 High-Growth Area rundown on why Vail keeps growing, what is being built, and what it costs. 16,994 — Vail CDP population in 2026 (per World Population Review). +20% — Population growth since the 2020 census (14,099). ~5,000 — Acres in the Rocking K master plan. ~700 — Occupied homes in Rocking K, with ~2,000 lots sold A Community That Has Roughly Doubled The growth story is in the census numbers. Per World Population Review, the Vail Census-Designated Place — an unincorporated area, not an incorporated town — reached a population of about 16,994 in 2026, up more than 20 percent from the 14,099 counted in the 2020 census and roughly 67 percent above the 10,208 recorded in 2010. The reading list is consistent: Vail is adding rooftops faster than most of the metro. Two things drive it. One is geography — Vail sits at the southeastern edge of the Tucson basin with open, developable land and direct access to Interstate 10 and the Houghton Road corridor that the region has spent years widening. The other is supply: builders have land to work here, and they are working it. The Engine: Rocking K The center of Vail's growth is Rocking K, a master plan that runs to nearly 5,000 acres south of Old Spanish Trail, with land reaching north toward the Rincon Mountains and Saguaro National Park. Per the community and the Rocking K HOA, it has close to 700 occupied homes and about 2,000 homesites sold to date, and it carries a deep builder roster — Lennar, Meritage, Richmond American, D.R. Horton, Pulte, Del Webb, Moderne Communities, and Mattamy Homes among them. That breadth is part of why the corridor keeps absorbing demand: with multiple builders pricing different product types side by side, a buyer touring Rocking K can compare floor plans and price points in a single afternoon, which is rare in the resale-heavy parts of the metro. Alamar (Mattamy Homes) (38 homesites, From 1,735 sq ft, Models Aug 2026): Per a June 2026 announcement, Mattamy's newest Rocking K neighborhood — 38 finished homesites on 4.7 acres, closed June 10, 2026, with four single-family floor plans starting at 1,735 square feet. Diamond Community Park (20 acres, Pickleball & basketball, Soccer fields): Per the community, a 20-acre park with soccer fields, basketball and pickleball courts, and playscapes, connected to homes by walking and biking trails. Trail & Park Access (The Loop nearby, Saguaro NP, Old Spanish Trail): Per the community, Rocking K sits minutes from Saguaro National Park and Colossal Cave Mountain Park and a short bike ride from The Loop, the region's 137-mile shared-use path system. The Newest Piece: Alamar The reason to flag Rocking K right now is its newest neighborhood. Per a June 2026 announcement, Mattamy Homes closed on Alamar at Rocking K — 38 finished homesites across 4.7 acres — on Wednesday, June 10, 2026. Presales are scheduled to begin in July, with model homes expected to open in August 2026, and Mattamy plans to offer four single-family floor plans starting at 1,735 square feet. Alamar joins the builder's two existing Rocking K neighborhoods, Covena Pointe and Oasis, deepening one builder's footprint inside the master plan — a useful signal of where the demand is, since builders buy finished lots when they expect to sell the homes on them. What's Within the Master Plan Rocking K is built around its outdoor access. Per the community, just outside the homes are walking and biking trails that connect residents to a 20-acre Diamond Community Park, which includes soccer fields, basketball and pickleball courts, and playscapes; a larger resort-style recreation center is proposed at the heart of the community. The location does a lot of the work, too: Saguaro National Park, Colossal Cave Mountain Park, and the planned Bike Ranch Resort sit minutes away along Old Spanish Trail, and the community is a short bike ride from The Loop — the region's roughly 137-mile car-free path network that links parks, greenways, and employment centers across the metro. For buyers who want new construction with direct access to open desert, that combination is the draw. Quick reference (June 26, 2026): Vail is an unincorporated community southeast of Tucson; per World Population Review its 2026 population is about 16,994, up more than 20% since the 2020 census. Rocking K is a roughly 5,000-acre master plan along Old Spanish Trail, ~25 miles from downtown Tucson, with nearly 700 occupied homes and ~2,000 lots sold. Newest neighborhood: Alamar by Mattamy Homes — 38 homesites, closed June 10, 2026, presales in July, models in August 2026, plans from 1,735 sq ft. Plans, prices, and timelines change — confirm with the builder before relying on any single figure. The Real-Estate Context: Vail Pricing On price, Vail runs roughly in line with the broader Tucson metro. Per Redfin, the median sale price across home types in Vail was about $400,000 in May 2026, at roughly $215 per square foot, with homes typically going under contract in a couple of months. Per Zillow, the typical Vail home value sat near $413,000 as of spring 2026, down about 2.3 percent over the prior year — a modest cooling that mirrors much of Southern Arizona. None of this is investment advice; it is context for why a buyer comparing established resale neighborhoods closer in often ends up touring Vail, where the trade-off is a longer commute for newer construction, larger lots, and a still-filling master plan with amenities on the way. Sources World Population Review — "Vail, Arizona Population 2026" (worldpopulationreview.com/us-cities/arizona/vail) — accessed June 26, 2026 — for the Vail CDP's 2026 population near 16,994, the 20%-plus growth since the 14,099 counted in the 2020 census, and the 10,208 recorded in 2010. PR Newswire / citybiz — "Mattamy Homes Expands Presence at Rocking K with Acquisition of Alamar Neighborhood in Vail, Arizona" (prnewswire.com; citybiz.co/article/865311) — accessed June 26, 2026 — for the June 10, 2026 close on Alamar at Rocking K, the 38 finished homesites across 4.7 acres, the July presales and August 2026 model-home timing, the four floor plans starting at 1,735 square feet, the ~5,000-acre master plan, the ~25-mile distance from downtown Tucson, and Mattamy's Covena Pointe and Oasis neighborhoods. Rocking K (liverockingk.com) and the Rocking K HOA (rockingkhoa.com) — accessed June 26, 2026 — for the nearly 5,000-acre master plan along Old Spanish Trail at the base of the Rincon Mountains next to Saguaro National Park, the close-to-700 occupied homes and ~2,000 homesites sold, the builder roster (Lennar, Meritage, Richmond American, D.R. Horton, Pulte, Del Webb, Moderne Communities, Mattamy), the 20-acre Diamond Community Park with soccer fields and basketball and pickleball courts, the proposed recreation center, and the trail access to Saguaro National Park, Colossal Cave Mountain Park, and The Loop (~137 miles). Redfin — "Vail Housing Market" (redfin.com/city/26454/AZ/Vail/housing-market) — accessed June 26, 2026 — for the median sale price near $400,000 in May 2026 at about $215 per square foot. Zillow — "Vail, AZ Housing Market" (zillow.com/home-values/21021/vail-az) — accessed June 26, 2026 — for the typical Vail home value near $413,000 in spring 2026, down about 2.3 percent year over year. All data current as of June 26, 2026; population, prices, and builder plans change, so confirm details directly with the builder or community before relying on any single one. This post is for informational purposes only and is not an offer to sell or a solicitation of an offer to purchase real estate.