St. Mark Golf Course occupies rolling terrain in Lake San Marcos, a planned residential community in northern San Diego County. The course was designed by Harry Rainville and David Rainville, a father-son team active in Southern California golf architecture during the mid-to-late twentieth century. The Rainvilles worked on numerous municipal and daily-fee layouts across the region, typically creating playable courses suited to the area's topography and climate. The routing at St. Mark takes advantage of the natural contours around Lake San Marcos, with several holes playing along or near the water. The layout features elevation changes characteristic of the inland valleys of San Diego County, where fairways often move through gentle hills and native vegetation. The course serves both residents of the surrounding community and outside visitors, functioning as a neighborhood amenity within the broader Lake San Marcos development. The design emphasizes accessibility for a range of skill levels while incorporating enough strategic interest to reward thoughtful play. Mature trees and landscaping have developed over the decades since opening, framing holes and adding definition to the routing. The course remains a fixture of the local golf scene in northern San Diego County, offering a straightforward test of golf in a setting shaped by Southern California's characteristic climate and landscape.