The I-90 Corridor: Mullan Road History, Forest Land Constraints, and Landlording Between Missoula and Idaho
Mineral County exists because of its corridors. The Mullan Road — the first engineered road across the northern Rockies, built by Army Lieutenant John Mullan between 1859 and 1862 to connect Fort Benton on the Missouri River with Fort Walla Walla on the Columbia — followed the St. Regis and Clark Fork river valleys through what would become Mineral County. The Northern Pacific Railroad followed the same corridor in the 1880s. The Chicago, Milwaukee, St. Paul and Pacific Railway (the Milwaukee Road) built a parallel line through the county in 1907–1908. Interstate 90 completed the sequence in the 1960s, laying the modern highway directly over the path that Mullan’s road crews had cleared through dense timber a century earlier. Every community in Mineral County sits along this corridor — there is essentially no settlement away from the I-90/river valley axis, because the mountains that rise on either side are almost entirely national forest.
This corridor geography defines everything about Mineral County as a rental market. The entire population lives in a narrow ribbon of private land in the valley bottom, hemmed in by Lolo National Forest on all sides. Only about 5 percent of the county’s land is privately owned, which means that the total buildable area is extraordinarily limited for a county of 1,223 square miles. This scarcity of private land constrains the housing supply in a way that has no parallel in Montana’s prairie counties, where land availability is essentially unlimited, and it means that property values and rents reflect not just demand but the physical impossibility of significant new development in many locations.
Three Towns Along the Interstate
Mineral County’s three principal communities each serve different functions within the corridor. Superior, the county seat, was founded in 1869 and grew during the Cedar Creek gold rush of the 1860s and 1870s that brought several thousand miners to the mountains south of the Clark Fork. The 1920 courthouse remains in use. Superior hosts the county government offices, Mineral Community Hospital, Superior K-12 Schools, and the Mineral County Museum, which houses what is reputedly the finest collection of John Mullan and Mullan Road papers in existence. In 1908, the Superior Hotel became the first hotel to receive Gideon Bibles in its rooms — a piece of American hospitality history commemorated by a plaque on the Mullan Road.
St. Regis sits at the junction of the St. Regis River and the Clark Fork, where I-90 crosses Montana Highway 135 (the St. Regis to Paradise Scenic Byway). Its economy centers on I-90 traveler services — fuel, food, lodging, and the gift and travel center that markets huckleberry products and Montana souvenirs to interstate traffic. St. Regis is also the departure point for the Route of the Hiawatha, a 15-mile bike trail through tunnels and across trestles of the abandoned Milwaukee Road rail line that has become one of the most popular cycling attractions in the northern Rockies. The Hiawatha Trail generates meaningful seasonal tourism revenue and creates summer employment in St. Regis and at the Lookout Pass trailhead.
Alberton, nearest to the Missoula County line, is the community most affected by Missoula spillover. Originally a Milwaukee Road railroad town platted in 1905, Alberton today attracts residents who work in Missoula but prefer the lower property costs and rural character of the Clark Fork corridor west of the city. The Alberton Gorge — a dramatic stretch of the Clark Fork with Class II and III whitewater rapids framed by rose-colored cliffs — has become one of western Montana’s most popular rafting destinations, generating summer recreation traffic and supporting several outfitting companies. Alberton’s proximity to Missoula (about 30 miles) makes it the Mineral County community with the most potential for rental demand growth, particularly as Missoula housing costs continue to rise.
The Great Fire of 1910 and the Timber Legacy
Mineral County’s forests bear the legacy of the Great Fire of 1910 — the largest wildfire in American history, which burned approximately three million acres across Idaho and western Montana in just two days in August 1910, killed 85 people (mostly firefighters), and destroyed several Mineral County communities including much of Haugan and the timber operations around De Borgia. The fire fundamentally reshaped both the physical landscape and the institutional response to wildfire: it led directly to the aggressive fire suppression policies that the U.S. Forest Service would pursue for most of the twentieth century and transformed the Forest Service from a small land management agency into the firefighting organization that it remains today.
For the local economy, the 1910 fire’s aftermath created decades of salvage logging work and established timber as the county’s dominant industry for most of the twentieth century. The Historic Savenac Nursery, built in 1907 near Haugan, produced millions of tree seedlings for reforestation after the fire and employed hundreds of Civilian Conservation Corps workers during the 1930s. Today, timber remains a component of the local economy — corporate timber interests own approximately 8 percent of the county’s land — but it no longer provides the employment base it once did. Construction has overtaken timber as the county’s largest employment sector, employing 237 workers compared to retail trade (233) and healthcare (217).
Lookout Pass and Recreation Growth
Lookout Pass Ski and Recreation Area, located at the Idaho border where I-90 crosses the Bitterroot Range at 4,725 feet, receives approximately 400 inches of snow annually and provides affordable skiing and snowboarding that draws visitors from both the Missoula and Coeur d’Alene/Spokane markets. The ski area is also the northern trailhead for the Route of the Hiawatha bike trail during summer months. This dual-season recreation asset has helped position the western end of Mineral County as a modest recreation destination, supporting seasonal employment and generating lodging demand at the motels and vacation properties near Haugan and the Idaho border.
Fish Creek State Park, the second-largest park in Montana’s state park system, is located along the Clark Fork between Superior and Alberton and is home to the largest ponderosa pine tree in the state. The park provides camping, fishing, and hiking access and contributes to the outdoor recreation amenity package that has helped attract the lifestyle migrants who are driving the county’s 24-percent population growth since 2010.
The Missoula Commuter Dynamic
Mineral County’s most important long-term rental market trend is the Missoula commuter dynamic. As Missoula’s housing costs have risen — driven by the university, healthcare, technology, and lifestyle factors that have transformed Missoula into one of Montana’s most expensive housing markets — workers priced out of Missoula have increasingly looked west along I-90 for more affordable alternatives. Alberton, 30 miles west, and Superior, 57 miles west, both offer significantly lower housing costs, and the I-90 corridor provides a reasonable year-round commute to Missoula employment. This commuter dynamic has contributed to Mineral County’s population growth and has begun to put upward pressure on rents, particularly in the Alberton area.
For landlords, the Missoula commuter is an increasingly important tenant profile. These are typically workers employed in Missoula’s healthcare, retail, service, or construction sectors who earn Missoula wages but cannot afford Missoula rents. Their income is verifiable through Missoula employers, their employment tends to be stable, and their commitment to the Mineral County commute reflects a deliberate housing choice rather than a transient arrangement. The trade-off for landlords is that these tenants may relocate if Missoula housing becomes more accessible or if gas prices and commute fatigue push them back toward Missoula.
Mineral County landlord-tenant matters are governed by the Montana Residential Landlord and Tenant Act of 1977, MCA Title 70, Chapter 24, and the Montana Tenants’ Security Deposits Act, MCA Title 70, Chapter 25. Nonpayment notice: 3-day pay or vacate. Minor lease violation: 14-day cure or quit. Major lease violation: 3-day cure or quit. No-cause termination (month-to-month): 30-day written notice. Security deposit: no cap; 10-day return if no deductions, 30-day itemized return if deductions; must be held in separate bank account; bank name and address provided to tenant; 24-hour written cleaning notice required before deducting cleaning charges (MCA § 70-25-201(3)). Landlord entry: 24 hours’ advance written notice (MCA § 70-24-312). No rent control. No local ordinances beyond state law. Verify legal access and easements for remote properties. Federal lead paint disclosure required for pre-1978 properties. FED action filed at Mineral County Justice Court in Superior. Consult a licensed Montana attorney before taking legal action. Last updated: April 2026.
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