San Francisco District Senior Regulatory Project Manager Dr. Sarah Firestone led a field workshop Dec. 7 on the Corps’ wetland delineation process at a property in Sonoma County. Several recently-hired staff members on the SPN Regulatory Division Team, as well as District Commander Lt. Col. Kevin Arnett, took part in the half-day training in which they learned how to analyze plants and soils, identify hydrology indicators and map a wetland boundary at a tricky site with alkaline soils during a moderate drought.