Continuing to Provide Knowledgable and Realiable Drilling Services. Holt Services is the premier clean water, environmental and geotechnical contractor in the Pacific Northwest dating back to 1979. Our experienced, highly competent, management and field crews are the best in the industry and are able to complete tasks on time and under budget with safety as the highest priority. We offer the newest and most diverse drill rigs and support equipment available in the region and are rapidly expanding our fleet of new drilling rigs.