Loam
Three Bay Area patterns
Coastal forests around Wilder Ranch and El Corte de Madera can stay shaded after the sky clears. Mount Tamalpais and Redwood Regional Park show why a nearby ride can feel different: ridges get sun and wind, while wooded drainages hold moisture. Mount Diablo is a useful open-ridge comparison, but its low spots and approaches still need a check.
These examples help you choose a starting point. The full Bay Area directory includes every network in the region.
What affects drying time
Recent rain
A shower this morning can leave a trail wetter than a larger storm several dry days ago. Check when the rain fell as well as the total.
Shade
Redwood shade and short winter days slow drying. Open ridges get more sun and wind.
Drainage
Rocky slopes often drain sooner. Flat sections and depressions can hold water well after the rest of the trail looks ready.
Before you ride
Check the Mount Tamalpais State Park trail updates or the relevant local park notice before leaving. At the trailhead, look for soft ground and mud sticking to tires. If you are leaving ruts, give the trail more time.
Loam estimates conditions from recent weather, soil, terrain, and tree cover. Use the network pages below to check the latest estimate before you leave, then use the trailhead firmness check when you arrive.
Bay Area trail conditions
Coastal grassland and forest west of Santa Cruz, managed by California State Parks.
Redwood forest on the Peninsula, with shaded tread that can stay soft after a break in the rain.
Marin ridges and fire roads in Mount Tamalpais State Park. Check the park trail updates before riding.
East Bay hills above Oakland, where open ridges and shaded drainages can differ after the same storm.
Open East Bay slopes with exposed sections and low spots that can hold runoff.
Sources and method
Loam estimates conditions from weather, soil, and terrain. It does not measure the trail surface directly or override an official closure. Read how the estimate works and see the published checks and their limits.
- USDA NRCS: Hydrologic Soil Groups, soil infiltration and runoff.
- USGS: Infiltration and the Water Cycle, saturation, land cover, and slope.
These references explain physical processes, not the accuracy of Loam's predictions.
