and those not.
Rim of the World High School is there as well. . just east of Rte 189 turnoff to
Arrowhead Lake. The constructed portion of Route 18 begins at
State Route 210 and quickly enters the San Bernardino Mountains as a four-lane
expressway. SR 18 is known as Waterman Avenue in the city of
San Bernardino before turning into SR 18. The route climbs north at a gentle grade until it turns east, where it begins to offer panoramic views of San Bernardino. Hence, this portion of Route 18 is known as the
Rim of the World Highway. After meeting
State Route 138 at Mount Andreson Junction south of
Crestline, the expressway reverts to a two-lane mountain road. It meets two other highways,
State Route 189 just east of Arrowhead Highlands and
State Route 173 in
Lake Arrowhead, before running over
State Route 330 in
Running Springs. SR 18 continues through several valleys and near
ski resorts before reaching a summit. At that point, Route 18 again runs along a lengthy mountain ridge, offering more spectacular scenery at an even higher
elevation. At its west junction with
State Route 38 near the west corner of
Big Bear Lake, Route 18 jogs across a dam and travels along the south shore of Big Bear Lake. After going through
the City of Big Bear Lake, it overlaps with SR 38 and moves from the south to the north side of Bear Valley east of both Big Bear Lake and the Big Bear City airport before it descends from the mountains to the desert on the northerly side of the mountains, first heading northeast, briefly north, and then northwest. SR 18 at this point follows the cities on the north face of the San Bernardino Mountains in the Mojave Desert: In
Lucerne Valley, it turns west for 21 miles with SR 247 1/8th of a mile north of the bend. It goes past the east terminus of Bear Valley Road (a major Victor Valley area cutoff) outside of Apple Valley town limits as it becomes an expressway (Happy Trails Highway, given for the High Desert's residency and final resting place of the legendary singing cowboy,
Roy Rogers) through
Apple Valley and
Victorville. It joins with
Interstate 15 inside of Victorville (this is considered a discontinuity, since the freeway entries refer to I-15 only and not State Route 18, which has partial route markings along the freeway, mainly on southbound I-15) for a few miles to the southeast and south before taking off west across the desert, reducing into a two-lane highway again and meeting
U.S. Route 395 at the Victorville–
Adelanto border, crosses into Los Angeles County as the beginning of county-named Pearblossom Highway, and ending at
State Route 138 east of
Llano. SR 18 thus takes an unusual path in the shape of a
question mark. From SR 138 in Llano to I-15 in Victorville, it is signed as east-west. East of the 15, cardinal descriptions are not posted below the route markers, since it does not clearly go either east-west or north–south. Also notable is that State Route 18 and 138 cover each other in opposing termini, as SR 138 ends at its southmost point in Crestline with SR 18, while SR 18's northwest most endpoint is in Llano with SR 138. SR 18 is part of the
California Freeway and Expressway System, and in Apple Valley and west of I-15 are part of the
National Highway System, a network of highways that are considered essential to the country's economy, defense, and mobility by the
Federal Highway Administration. SR 18 is eligible to be included in the
State Scenic Highway System, but it is not officially designated as a scenic highway by the
California Department of Transportation. SR 18 from SR 138 at Crestline to SR 38 at the westernmost point of Big Bear Lake, and the SR 18/38 overlap in the City of Big Bear Lake, are designated as part of the
Rim of the World Scenic Byway, a
National Forest Scenic Byway. ==History==