Mission Viejo sits in the Saddleback Valley of southern Orange County, organized around the Oso Creek drainage rather than around a rectangular street grid. Arterial roads generally follow the valley floors while residential tracts sit on terraces, mesas and ridgelines above them. That single fact explains much of what an agent encounters on the ground: elevation changes, slope-backed lots, view differences from one street to the next, and neighborhoods that feel separate from one another even when they are a short drive apart.
Interstate 5 defines the western edge of the city and carries most regional commuting. SR-241 sits off the eastern and northeastern side and changes the practical commute picture for buyers working toward Irvine and the Spectrum. Marguerite Parkway is the primary north-south spine running most of the length of the city, with Felipe Road and Olympiad Road operating as secondary north-south routes, Olympiad tracking the eastern side of the lake basin.
East-west movement relies on a small number of arterials that also organize the market mentally: Los Alisos Boulevard at the north, Alicia Parkway through the northern and lake-adjacent areas, La Paz Road through the historic core and civic corridor, Oso Parkway through the central-south of the city and out to SR-241, and Crown Valley Parkway and Avery Parkway through the southern institutional district.
Lake Mission Viejo occupies the center-north of the city and is a genuine organizing feature of the housing market, not only an amenity. Oso Creek and its trail corridor run through the middle of the city and shape greenbelt adjacency, drainage and open-space backing for a large number of tracts.
Mission Viejo borders Lake Forest to the northwest, unincorporated Trabuco Canyon and Foothill Ranch to the north and northeast, Rancho Santa Margarita and the Ladera Ranch area to the east, San Juan Capistrano to the south, and Laguna Niguel and Laguna Hills to the west and southwest. Those adjacencies matter because they define the alternatives most Mission Viejo buyers are also considering.