Question: Lake Hodges is crossed by the major Interstate Highway that begins in what county?

Context paragraphs:
Lake Hodges Bridge: The Lake Hodges Bridge is a component of Interstate 15 that spans Lake Hodges, just south of Escondido, California.  Lake Hodges Bridge is an important part of San Diego's North-South transportation axis.

Interstate 87 (New York): Interstate 87 (I-87) is a 333.49 mi Interstate Highway located entirely within the U.S. state of New York, and is part of the main highway between New York City and Montreal.  The highway begins in the Bronx borough of New York City, just north of the Triborough Bridge.  From there, the route runs northward through the Hudson Valley, the Capital District, and the easternmost part of the North Country to the Canadian border in the Town of Champlain.  At its north end, I-87 continues into Quebec as Autoroute 15 (A-15).  I-87 connects with several regionally important roads: I-95 in New York City, New York State Route 17 (NY 17; future I-86) near Harriman, I-84 near Newburgh, and I-90 in Albany.  The route is the longest intrastate Interstate Highway in the Interstate Highway System.  The highway is not contigous with I-87 in North Carolina.

Interstate 85 in Virginia: Interstate 85 (I-85) is a part of the Interstate Highway System that runs from Montgomery, Alabama to Petersburg, Virginia.  In Virginia, the Interstate Highway runs 68.64 mi from the North Carolina state line near Bracey north to I-95 in Petersburg.  I-85 passes through the eastern part of Southside Virginia, where it parallels U.S. Route 1 (US 1) from Petersburg, where the highway runs concurrently with US 460, to south of South Hill, where the highway intersects Southside's major east–west highway, US 58.  The Interstate Highway is the primary connection between the Richmond–Petersburg metropolitan area and the Research Triangle and other major metropolitan areas of North Carolina.  Like all mainline Interstate Highways, I-85 is a part of the National Highway System for its entire length in Virginia.

Interstate 25: Interstate 25 (I-25) is a major Interstate Highway in the western United States.  It is primarily a north–south highway.  I-25 stretches from Interstate 10 at Las Cruces, New Mexico (approximately 25 mi north of El Paso, Texas), to Interstate 90 in Buffalo, Wyoming (approximately 60 mi south of the Montana/Wyoming border).

Lake Hodges: Lake Hodges is a lake and reservoir located in Southern California, about 31 mi north of San Diego and just south of Escondido, California.  When full, the reservoir has 1234 acre , a maximum water depth of 115 ft , and 27 mi of shoreline.  Lake Hodges has a total capacity of 30,251 acre-feet of water.  Interstate 15 crosses Lake Hodges via the Lake Hodges Bridge.  Approximately 1000 ft west of the I-15 freeway bridge is a bicycle/pedestrian bridge which opened on May 15, 2009 and is the longest stressed ribbon bridge in the world.

Interstate 55: Interstate 55 (I-55) is a major Interstate Highway in the central United States.  As with most interstates that end in a five, it is a major cross-country, north-south route, connecting the Gulf of Mexico to the Great Lakes.  The highway travels from LaPlace, Louisiana, at I-10 to Chicago at U.S. Route 41 (US 41, Lake Shore Drive), at McCormick Place.  The major cities that I-55 connects to includes (from south to north) Jackson, Mississippi; Memphis, Tennessee; and St. Louis.

Interstate 15: Interstate 15 (I-15) is a major Interstate Highway in the western United States.  I-15 begins near the Mexico–US border in San Diego County and stretches north to Alberta, Canada, passing through the states of California, Nevada, Arizona, Utah, Idaho, and Montana.  The interstate serves the cities of San Diego, Las Vegas, St. George, Salt Lake City, Pocatello, Idaho Falls, and Butte.  It also passes close to the urban areas of Orange County, California, Los Angeles County, California, Provo, Utah, Ogden, Utah, and Helena, Montana.  The stretches of Interstate 15 in Idaho, Utah, and Arizona have been designated as the "Veterans Memorial Highway".

Interstate 75: Interstate 75 (I-75) is a major Interstate Highway in the Great Lakes and Southeastern regions of the United States.  As with most Interstates that end in a five, it is a major cross-country, north–south route, one of the longest in the U.S., from southern Florida to the northern tip of Michigan.  It travels from State Road 826 (SR 826, Palmetto Expressway) and SR 924 (Gratigny Parkway) on the Hialeah–Miami Lakes border (northwest of Miami, Florida) to Sault Ste. Marie, Michigan, at the Canadian border.  I-75 is the seventh longest Interstate Highway, the second longest north-south after I-95, and passes through six different states: Florida, Georgia, Tennessee, Kentucky, Ohio, and Michigan.  The major cities that I-75 connects to includes (from south to north) Tampa, Atlanta, Cincinnati, and Detroit.

List of gaps in Interstate Highways: There are gaps in the Interstate Highway system, where the roadway carrying an Interstate shield does not conform to the standards set by the Federal Highway Administration (FHWA), the body that sets the regulations for the Interstate Highway System.  For the most part, the Interstate Highway System in the United States is a connected system, with most freeways completed; however, some Interstates still have gaps.  These gaps can be due to unconnected segments of the same route or from failure of the road to fully conform to Interstate standards by including such things as at-grade crossings, traffic lights, undivided or narrow freeways, or movable bridges (lift bridges and drawbridges).  This article deals with present-day gaps, as such examples were far more numerous during construction of the Interstate Highway System and the upgrading of existing roads to meet these standards, which did not occur everywhere at the same time.  Temporary gaps, such as lane closures that reduce traffic to one lane and reduce speed limits, are also excluded.

Interstate 80 in New Jersey: Interstate 80 (I-80) is a major Interstate Highway in the United States, running from the New York City Metropolitan Area westward to San Francisco, California.  The New Jersey Department of Transportation also identifies I-80 as the Christopher Columbus Highway.  I-80 in New Jersey runs 68.54 mi from the Delaware Water Gap Toll Bridge over the Delaware River at the Delaware Water Gap to its eastern terminus at I-95 in Teaneck, Bergen County.  I-95 continues from the end of I-80 to the George Washington Bridge for access to New York City; access is also provided via the I-280 spur towards the Holland Tunnel and US 46 to Route 3, or I-95, towards the Lincoln Tunnel.  Throughout New Jersey, I-80 runs parallel to US 46.  The highway heads through rural areas of Warren and Sussex counties before heading into more suburban surroundings in Morris County.  As the road continues into Passaic and Bergen counties, it heads into more urban areas.

Supporting paragraphs: Lake Hodges Interstate 15
Answer: San Diego County