Excavation & Site Prep in Detroit, Oregon: 2026 Guide

Excavation and Site Prep at Detroit Lake

Detroit sits high in the Santiam Canyon on Detroit Lake, in Marion County, where Highway 22 climbs into the Cascades. Excavation here is mountain dirt work: steep grades that have to be cut and benched, soils that stay saturated through a long wet season, deep frost in winter, and a town still rebuilding after the 2020 Beachie Creek Fire wiped out most of it. Whether you are clearing a burned lot, prepping a pad for a new lakeside home, or fixing a drainage problem on a grade, the dirt has to be handled with grade and water in mind first.

Cojo Excavation & Asphalt runs excavation and site prep for Detroit and the upper canyon from our Willamette Valley base, an easy run up Highway 22 to the lake. We bring the equipment and the judgment to read mountain ground.

What Excavation Covers in Detroit

Excavation is everything that happens before construction or paving. In a mountain setting, the common scopes are:

• Site grading and pad prep — Cutting and filling sloped, lakeside ground into a stable, well-draining building pad or driveway base.
• Drainage and water management — French drains, swales, and culverts to move water off a site before it undermines anything. The defining challenge up here.
• Utility trenching — Excavating and backfilling for water, power, septic, and other lines, with proper compaction so the ground does not settle.
• Land clearing — Removing brush, stumps, dead timber, and debris, which is heavy demand on burned rebuild parcels.
• Wildfire rebuild site prep — Clearing, grading, and pad work for properties coming back after Beachie Creek.

The variables that drive scope and cost are in our excavation cost in Oregon and site grading cost in Oregon guides.

Industry Baseline Pricing for Excavation

Excavation is the hardest service to price without seeing the ground, because much of the cost is hidden until you dig. The figures below are industry baseline ranges, not quotes. Mountain work with rock, steep grade, deep frost, or long haul-off frequently exceeds them.

Industry baseline ranges. Actual cost depends on soil, rock, slope, access, haul-off, and scope.

Scope	Industry Baseline Range
Site grading	$1.50–$4 per square foot
Land clearing (light to moderate)	$1,500–$5,000 per acre
Utility trenching	$10–$25 per linear foot
Drainage / French drain	$20–$40 per linear foot
Hourly excavator + operator	$150–$300 per hour
Haul-off / disposal	varies by volume and distance

The wild cards at Detroit are rock and water. Cascade ground hides ledge rock that slows digging, and lakeside parcels can carry a high water table that changes how you trench and drain. A site visit is the only honest way to scope it.

Water Is the Mountain's Defining Problem

If one factor separates a good Detroit excavation job from a bad one, it is water. The upper canyon gets soaked for months, snowmelt adds to it, and sloped lakeside lots collect runoff from everything above them. Bad drainage shows up as a soggy site, a failing driveway base, water in a crawlspace, or erosion cutting toward the lake.

We design grading and drainage to move water on purpose: crown surfaces, cut swales, set culverts where flow concentrates, and run French drains where groundwater needs an exit. Handled at the excavation stage, this protects everything built on top, including any asphalt paving in Detroit that follows. Skipped, water finds the weak point and the repairs cost far more than the drainage would have.

Wildfire Rebuild Site Work

The Beachie Creek Fire leveled most of Detroit, and rebuild site prep remains the steady need up here. These projects start by clearing remaining debris and dead timber, then grading a stable pad, then trenching for the utilities the new structure requires. Because the ground may have shifted or eroded since the fire, we re-evaluate drainage from scratch rather than assuming the old layout still works. The site prep is the literal foundation for everything the rebuild puts on top of it.

Call Before You Dig: 811 and Permits

Every Oregon excavation job starts with an 811 locate. Before any bucket goes in the ground, underground utilities get marked, which protects you, us, and the lines. We handle the locate as standard practice. Larger site work in Marion County can trigger erosion-control and grading permits, and work touching the Highway 22 right-of-way may require ODOT coordination. We know the thresholds and build the permitting into the plan.

Why Detroit Property Owners Choose Cojo

Mountain excavation is not valley dirt work. The grades are steeper, the water and snow are heavier, and access can be tight. We bring the right machines and the experience to read Cascade ground, whether that means catching a drainage problem before it becomes a foundation problem or recognizing when a slope needs benching instead of a straight cut. The run up Highway 22 to the lake is routine, and we would rather scope a job accurately than lowball it and hit surprises.

Browse our completed grading and site work on the portfolio page, or learn more about our site prep and grading services across the canyon and valley.