The 48th and 49th are partitioned by Gavilan Mountain Rd, Sandia Creek Dr, De Luz Rd, Marine Corps Base Pendleton, Sleeping Indian Rd, Tumbleweed Ln, Del Valle Dr, Highland Oak St, Olive Hill Rd, Via Puerta del Sol, N River Rd, Highway 76, Old River Rd, and Little Gopher Canyon Rd.
The 48th and 50th are partitioned by Gopher Canyon Rd, Escondido Freeway, Mountain Meadow Rd, Hidden Meadows, Reidy Cyn, N Broadway, Cougar Pass Rd, Adagio Way, Calle Ricardo, Tatas Place, Rue Montreux, Jesmond Dene Rd, Ivy Dell Ln, N Centre City Parkway, Highway 15, Richland Rd, Vista Canal, Woodland Parkway, W El Norte Parkway, Bennett Ave, Elser Ln, Nordahl Rd, Calavo Dr, Deodar Rd, Highway 78, Barham Dr, 2315-2339 Meyers Ave, Hill Valley Dr, County Club Dr, Auto Park Way, Highway 56, N Centre City Parkway, W Valley Parkway, N Juniper St, Highway 78, N Hickory St, E Mission Ave, Martin Dr, E Lincoln Ave, N Ash St, E Grand Ave, Bear Valley Parkway, Old Guerjito Rd, San Pasqual Battlefield State Historic Park, San Pasqual Trails Openspace, San Dieguito River Park, Bandy Canyon Rd, Santa Maria Creek, Highland Valley Rd, West Ridge Trail, Palmer Dr/Summerfield Ln, Pomerado Rd, and Carmel Mountain Ranch Openspace.
The 48th district takes in the cities of Santee, Poway, and northern Escondido, as well as the census-designated places Ramona, Rancho San Diego, Winter Gardens, Bostonia, Alpine, Campo, Hidden Meadows, Fallbrook, Valley Center, Bonsall, Rainbow, Pala, Borrego Springs, Julian, San Diego Country Estates, Eucalyptus Hills, Lakside, Granite Hills, Jamul, Casa de Oro-Mount Helix, Crest, Harbison Canyon, Descanso, Pine Valley, Mount Laguna, Portero, Boulevard, and Jacumba.
They are partitioned by Ortega Highway, Tenaja Truck Trail, NF-7506, Tenaja, San Mateo Creek, Los Alamos Rd, Und 233, S Main Dv, Wildomar, Grand Ave, Rancho Mirlo Dr, Copper Canyon Park, 42174 Kimberly Way-35817 Darcy Pl, Escondido Expressway, Scott Rd, 33477 Little Reb Pl-33516 Pittman Ln, Keller Rd, Menifee Rd, Clinton Keith Rd, Max Gilliss Blvd, Highway 79, Borel Rd, Lake Skinner, Warren Rd, Summitville St, Indian Knoll Rd, E Benton Rd, Rancho California Rd, Overhill Rd, Green Meadow Rd, Crossover Rd, Exa-Ely Rd, Denise Rd, Wiley Rd, Powerline Rd, Wilson Valley Rd, Wilson Creek, Reed Valley Rd, Centennial St, Beaver Ave, and Lake Vista Dr.
After the 2020 United States census, the district was moved to the inland portion of San Diego County, including Fallbrook, Murrieta, Temecula, Pauma Valley, Warner Springs, Borrego Springs, Santa Ysabel, Julian, Ramona, Poway, Santee, Lakeside, Descanso, Jamul, Dulzura, Alpine, Pine Valley, Campo, Jacumba Hot Springs, all of San Diego's Mountain Empire, San Diego's Indian reservations and portions of northern Escondido, and eastern La Mesa.