Mammoth Lakes 395 Wildlife Crossing (Potholing Operations)

The California Department of Transportation District 9 is conducting the Mammoth Lakes 395 Wildlife Crossing project in Mono County to support the development of wildlife crossing structures on U.S. Route 395. The scope of work includes geotechnical drilling and potholing operations to collect critical soil information and identify existing underground utilities. Specifically, the project involves five mud-rotary borings up to 70 feet deep, with two borings at post mile R19.79 and three at post mile 20.23, as well as potholing operations at eight locations along southbound US 395 at post miles 19.6 and 20.2. All activities will be performed entirely within the Caltrans right-of-way on previously disturbed areas, with no anticipated impacts to vegetation or environmental resources. Geotechnical operations include the collection of cuttings in 55-gallon drums for offsite disposal and the backfilling of 4-inch diameter holes with cement grout. The project is classified under NAICS code 541380 and has been granted a Notice of Exemption under Categorical Exemption 15306 Class 6. Primary administrative oversight is provided by the District 9 office in Bishop, California.