Timber harvest operations in Oregon's forests need reliable access from processing areas (log landings) to haul roads that move logs to mills. Skid trails and temporary roads often cross streams that have federal and state protections. ESA-listed salmon and steelhead make fish passage a requirement, not an option. Stream crossing restrictions also come from the Oregon Removal-Fill Law, which requires permits for 50 or more cubic yards of fill or removal in state waters, and from the Oregon Forest Practices Act, which mandates that stream crossings minimize disturbance and allow fish movement.
Culverts were once the standard solution, but they restrict juvenile fish movement, trap sediment and debris, and violate current fish passage standards when the fill depth exceeds natural channel dimensions. Open-bottom structures and bridges have become the preferred choice for new crossings and habitat restoration. An open-span timber bridge allows unobstructed stream flow and fish passage while supporting the full load of loaded log trucks needed during harvest operations.
Why Timber Bridges for Log Landing Access
Fish Passage Compliant
Open-span design preserves full channel width and depth, meeting ODFW fish passage criteria and ESA habitat requirements for coho salmon, steelhead, and bull trout.
Avoids Removal-Fill Permits
Bridge abutments place no material in the stream channel, avoiding the 50+ cubic yard fill threshold that triggers Oregon DSL Removal-Fill Law permitting.
Load Rated for Log Trucks
The SL40-10-28 handles 56,000 lb fully loaded log trucks, and the SL40-12-40 steps up to 80,000 lb for operations running maximum weight limits on public roads.
Same-Day Installation
Bridge arrives fully assembled and can be placed with equipment already at the landing. No concrete curing and no specialized crew needed.
Meets Forest Practices Act
Open-span design satisfies Oregon's requirement to minimize stream disturbance. PE-stamped engineering documentation supports permitting and OFCO compliance.
Relocatable Between Harvest Units
The bridge can be moved to serve multiple crossings across consecutive harvest seasons, extending its value across the landscape.
Recommended Model for Log Landing Access
Log operations need a bridge that handles the full range of harvest equipment. Fully loaded log trucks approach 56,000 lbs on Oregon public roads, which makes the SL40-10-28 the standard choice for log landing to haul road connections. For operations that load trucks to the 80,000 lb federal weight limit and haul on federal highways or private roads, the SL40-12-40 provides the extra capacity. Both models span the typical clear distances needed for small to medium streams in Oregon timber country.
40-foot stress-laminated timber bridge constructed from 2" x 10" CCA-treated southern yellow pine, encased in 10" x 25 lb/ft structural steel channel. Arrives fully assembled with all hardware, curb beams, and shear plates.
Full two-panel (13 ft wide) configuration is standard. Contact us for current inventory and pricing.
How It Compares
Timber contractors and industrial forestry operations evaluate several crossing options for log landing access: culverts, steel portable bridges, and open-span timber structures. Each has different performance characteristics for this specific application.
| Factor | Timber Bridge | Pipe Culvert | Steel Portable Bridge |
|---|---|---|---|
| Fish Passage | Full compliance | Restricts movement | Varies by design |
| Install Time | Hours (same day) | Days (excavation + backfill) | Hours to days |
| Fill Disturbance | None (DSL exempt) | 50+ CY fill (DSL permit required) | Varies |
| Stream Ecology | Preserves habitat | Clogs, traps sediment | May restrict flow |
| Log Truck Load Rating | 56,000 to 80,000 lb | Varies by size | Usually 40,000 lb or less |
| Equipment for Install | On-site loader/excavator | Crane, heavy equipment | Varies |
| Relocatable | Yes | No | Yes (limited use) |
Permitting in Oregon
Stream crossings in Oregon timber operations are regulated at both the state and federal level. The Oregon Removal-Fill Law, administered by the Oregon Department of State Lands (DSL), requires permits for 50 or more cubic yards of fill or removal in waters of the state. Open-span bridges that place abutments on the banks with no material in the channel typically avoid this requirement, eliminating a significant permitting step. The Oregon Forest Practices Act requires that stream crossings minimize disturbance and allow fish passage. SSBT (salmon, steelhead, bull trout) habitat rules from 2017 specify wider riparian buffers and mandate that stream-crossing structures maintain or enhance habitat function.
At the federal level, the Army Corps of Engineers Portland District administers Section 404 Clean Water Act permits. For crossings in listed fish habitat, NOAA Fisheries may also be involved in consultation. Open-span timber bridges frequently qualify for streamlined permitting because they avoid fill material and maintain natural channel function, reducing environmental review burden compared to culvert installations.