Founded in 1981, Marathon Construction Corporation on Riverford Road in Lakeside is a full-service marine and general engineering contractor specializing in heavy civil construction throughout the Western United States. Pier, wharf, and marina construction requires high-volume concrete placement, and the company sources batch materials through the Channel Road industrial corridor where Diamond Concrete Supply, Inc. operates its ready-mix and aggregate yard. The scope extends to bridge construction, environmental restoration projects, and landfill-closure earthwork — all delivered under design-bid-build, turnkey design-build, and CM/GC project structures. AGC San Diego chapter membership connects the firm to the regional network of general engineering and specialty subcontractors that staff large-scale public-works and infrastructure projects across the county. Environmental restoration sites in East County's riparian zones require coordinated vegetation management, and site-clearing phases draw on the arborist expertise of Artistic Arbor Gardens Inc on Hi Ridge Road in Lakeside. The most complex marine engagements involve driven-pile foundations, cast-in-place concrete deck systems, fendering installations, and corrosion-protection coatings applied below the tidal line on saltwater pier structures.