Acquiring 100 contiguous acres of raw Colorado land for $37,750—equating to an exceptional $377.50 per acre—represents one of the lowest entry costs per acre anywhere in the Western United States. Located in Costilla County near the intersection of Aztec Avenue and County Road 65 in San Luis, Colorado (ZIP 81152), this expansive parcel sits roughly seven minutes east of State Highway 159, positioned between the historic town of San Luis and Fort Garland.
Offered at $0.0087 per square foot of land with an annual tax bill of $805.00 per year ($67.08 per month), this unimproved agricultural (AG) parcel provides a massive land footprint for off-grid homesteading, livestock grazing, solar energy setups, or long-term speculative land banking. However, purchasing 100 acres in the San Luis Valley at $377 per acre requires a clear understanding of its physical and legal realities: the property is offered as a cash-only transaction with no owner financing, operates entirely off-grid, and requires independent water, septic, and power infrastructure.
Property Overview and Specification Summary
Establishing official listing disclosures, county tax records, and site parameters provides the baseline for evaluating this Costilla County asset.
| Property Parameter | Official Listing Disclosures & Public Records |
| Street Address / Location | 100 AC Aztec Avenue, San Luis, CO 81152 |
| County / Region | Costilla County / San Luis Valley Submarket |
| Parcel Identification Number | 10007300 |
| Current Asking Price | $37,750 (Listed August 28, 2026) |
| Total Land Footprint | 100.00 Acres (4,356,000 Square Feet) |
| Price Per Acre | $377.50 per acre |
| Price Per Square Foot of Land | $0.0087 per sq. ft. (less than 1 cent per sq. ft.) |
| Zoning Classification | AG (Agricultural Zoning) |
| Topography & Vegetation | Flat High-Desert Plain, Sagebrush, Low Shrubs |
| Road Access Surface | Unpaved Dirt / Gravel (Aztec Ave / County Road 65) |
| Utility Infrastructure | 100% Off-Grid (No Power Lines, Well Needed, Septic Needed) |
| Annual Property Taxes | $805.00 per year ($67.08 per month / $8.05 per acre annually) |
| Homeowners Association (HOA) | None ($0.00 / month) |
| Purchase Terms | Cash Only (No Seller Financing Offered) |
Financial Metrics and Per-Acre Price Analysis
Evaluating a 100-acre land purchase at $37,750 requires placing its unit pricing against regional Costilla County benchmarks and fixed holding costs.
Per-Acre and Unit Area Calculations
- Purchase Price: $37,750
- Price Per Acre: $37,750 ÷ 100.0 acres = $377.50 per acre
- Total Square Footage: 100.0 acres × 43,560 sq. ft. = 4,356,000 square feet
- Price Per Square Foot of Land: $37,750 ÷ 4,356,000 sq. ft. = $0.00867 per sq. ft.
In the San Luis Valley, smaller 5-acre subdivision lots in Sangre de Cristo Ranches or Wild Horse Mesa often sell for $1,200 to $3,500 per acre ($6,000 to $17,500 total). By purchasing in bulk at 100 acres, the unit rate drops to $377.50 per acre, delivering an approximate 70% to 80% discount per acre compared to smaller residential sub-parcels in the region.
Fixed Holding Overhead and Carrying Costs
- Annual Property Tax Bill: $805.00 per year
- Monthly Tax Burden: $805 ÷ 12 months = $67.08 per month
- Annual Tax Cost Per Acre: $805 ÷ 100.0 acres = $8.05 per acre annually
- HOA Fees: $0.00 per month
Carrying costs of $67.08 per month ($8.05 per acre per year) mean that an investor or off-grid developer can hold title to a 100-acre Colorado estate with minimal ongoing capital drain.
Land Characteristics, Topography, and Access Dynamics
The physical environment of 100 AC Aztec Avenue dictates its operational use and site preparation requirements.
- High-Desert Flatland Terrain: Situated in the heart of the San Luis Valley at an elevation of approximately 7,500 feet, the terrain is largely level flatland covered in native sagebrush and high-desert grasses. The flat contour significantly reduces grading and excavation costs compared to steep mountain parcels.
- Panoramic Mountain Views: The open valley floor provides unobstructed 360-degree views of the Sangre de Cristo Mountain Range to the east and the Culebra Range to the south.
- Road Access Logistics: Access is via unpaved county and local dirt roads (County Road 65 and Aztec Avenue). While accessible via standard truck or SUV in dry weather, high-desert dirt roads can become muddy during winter snowmelt or late-summer monsoons, making 4WD vehicles recommended.
- Proximity to Highway 159: Located roughly seven minutes east of State Highway 159, keeping the property within reasonable driving distance of basic amenities in San Luis (Colorado’s oldest town) and Fort Garland.
Agricultural Zoning (AG) & Costilla County Off-Grid Regulations
Understanding Costilla County’s regulatory framework is essential for buyers planning to build or camp on agricultural acreage.
- Agricultural (AG) Zoning Uses: AG zoning allows for traditional farming, livestock grazing, equestrian use, personal homesteads, and agricultural outbuildings.
- Minimum Dwelling Size: Costilla County land-use codes mandate that any single-family permanent dwelling must have a minimum footprint of 600 square feet for a single-story build. Tiny homes under 600 sq. ft. on permanent foundations are generally not permitted as primary residences.
- Short-Term Camping Policies: Landowners may camp on their property for up to 14 days every 3 months without a permit.
- Long-Term RV Camping Permits: Extended RV camping (up to 180 days per calendar year) requires obtaining a Long-Term Camping Permit ($200 fee) from Costilla County. To qualify, the county mandates that an approved septic system and a certified water source (well or installed cistern) be installed on-site.
- Water Well Permitting: In Colorado, drilling a groundwater well requires applying for a permit through the Colorado Division of Water Resources (DWR). On 100 acres, obtaining a household-use well permit (which typically allows domestic inside-use, watering of domestic animals, and limited outdoor irrigation) is generally straightforward due to the large parcel footprint.
Comparative Value Analysis: Subject Property vs. Regional Alternatives
To measure the market position of 100 AC Aztec Avenue, consider how it compares against alternative acreage options in Costilla County:
| Property Option | Total Acreage | Purchase Price | Price Per Acre | Zoning & Access | Infrastructure |
| 100 AC Aztec Ave (Subject) | 100.00 Acres | $37,750 | $377.50 / acre | AG / Dirt Road Access | 100% Off-Grid |
| Standard SDCR Subdivision Lot | 5.00 Acres | $12,500 | $2,500.00 / acre | Residential / Mountain Dirt | Off-Grid |
| Mid-Sized Valley Parcel | 35.00 Acres | $24,500 | $700.00 / acre | Estate / Rural Dirt | Off-Grid |
Comparative Takeaway
Purchasing 100 acres for $37,750 ($377.50/acre) offers superior economies of scale. While smaller 5-acre lots carry lower total purchase prices, their per-acre costs are over six times higher than this 100-acre tract.
Key Advantages and Primary Red Flags
Key Advantages
- Unbeatable Per-Acre Price: $377.50 per acre represents an ultra-low entry price for 100 acres of Colorado land.
- Low Holding Overhead: Annual property taxes total $805 per year ($67.08/month) with $0 HOA fees.
- Level Building Contours: Flat terrain eliminates heavy hillside excavation and retaining wall costs.
- Agricultural Flexibility: AG zoning supports livestock, horses, farming, and off-grid homesteading.
- Massive Land Buffer: 100 acres ensures total privacy and separation from neighbors.
Primary Red Flags and Site Limitations
- Cash-Only Mandate: The seller requires cash at closing and will not consider owner financing or land contracts.
- Zero Existing Utilities: No electrical lines, well, or septic system exist on the property.
- Unpaved Dirt Road Ingress: Requires navigating unpaved rural roads that may require 4WD during wet weather.
- High Altitude & Weather Extremes: San Luis Valley sits at ~7,500 feet, experiencing cold winter temperatures and windy high-desert conditions.
Target Buyer Profiles
| Buyer Profile | Compatibility Profile | Fit Assessment |
| Off-Grid Homesteaders & Ranchers | Buyers seeking large acreage for livestock, solar power setups, and private homesteading without HOA interference. | Ideal Fit |
| Cash Land Speculators & Investors | Investors looking to bank 100 acres of Western land at $377/acre with low $67/month carrying costs. | Ideal Fit |
| Equestrian & Agricultural Operators | Buyers needing open high-desert acreage for horse grazing, pole barns, or seasonal livestock turnout. | Ideal Fit |
| Suburban Turnkey Homebuilders | Purchasers requiring municipal city water, sewer drops, paved road access, and nearby retail centers. | Unfavorable Fit |
Essential Buyer Due Diligence Checklist
- Verify Location via GIS & OnX Hunt: Download the OnX Hunt app or use handheld GPS to navigate County Road 65 and Aztec Avenue to locate exact property boundary pins across the 100 acres.
- Consult Colorado Division of Water Resources: Check state well logs for neighboring parcels (Parcel #10007300) to estimate groundwater table depths and well drilling costs.
- Review Costilla County Building & Camping Codes: Confirm 600 sq. ft. minimum home size rules and RV camping permit requirements with the Costilla County Planning Department.
- Evaluate Solar Power Exposure: Measure unobstructed solar path access for a ground-mounted photovoltaic (PV) array and battery bank.
- Confirm Title & Tax Status: Verify fee-simple title conveyance and confirm that 2025/2026 property taxes ($805/year) are paid current prior to closing.
100 AC Aztec Avenue in San Luis, Colorado, provides a rare combination of massive acreage and ultra-low unit pricing. Offered at $37,750 ($377.50 per acre) for 100 flat, high-desert acres, its primary strengths include its unbeatable per-acre value, AG zoning flexibility, low $67.08/month property taxes, and panoramic mountain views.
The primary trade-offs are its cash-only purchase terms, 100% off-grid status, and the necessity of installing private water and septic infrastructure. For cash buyers, off-grid homesteaders, or land-banking investors seeking large-scale Colorado property under $40,000, this parcel represents an exceptional value proposition.
Listed on Zillow