Mr. Klevenhagen has nearly 20 years of combined experience in multiple phases of geotechnical & structural engineering, providing consultative services, construction monitoring, and material testing for builders, developers, contractors & architects.

Mr. Klevenhagen is the president & principal engineer of Construction Inspection Services, Inc., established 1988, & the president and principal engineer of CIS Engineering, Inc., established 1999. Consulting firms providing professional engineering services including the design & evaluation of timber, concrete, steel & masonry structures. Concrete & soil testing related to land development and foundation engineering.

Mr. Gary has nearly 20 years of combined experience in multiple phases of geotechnical engineering, construction monitoring, and materials testing for residential, commercial, and industrial development. Mr. Gary has designed hundreds of retaining walls throughout Maryland, Washington, D.C., Virginia, and Pennsylvania. Major areas of responsibility have included on-site monitoring of construction activities, management of an accredited soils and concrete testing laboratory, and geotechnical engineering. Programs have covered shallow and deep foundation systems; rigid and flexible pavement; embankment design and failure analyses; modular block, masonry, concrete and timber retaining wall design; groundwater control; stormwater management and infiltration explorations; settlement analysis; explorations and construction recommendations in problem soils conditions such as Karst Terrain (limestone), Marine clays and Diatomaceous soils; subsurface electromagnetic imaging; as well as other aspects of geotechnical engineering.