Sunrise Highway is a very scenic roadway east of San Diego. Shown here is an old alignment of the roadway, bypassed in the late 1950’s. The old alignment was more prone to snow and ice than the current one, hence the relocation from the north slope to the south slope. This photo was taken in November 2009.
The first section of the San Diego Freeway in San Diego (US 101 at the time) to be constructed was the Mission Bay Bypass in 1954. Elements of this construction can still be seen today, such as some older curbing at the intersection of Damon Ave and Santa Fe St. North and south of this small section of freeway, it was still a narrower four-lane roadway with some expressway sections. Between 1966 (north) and 1969 (south), the adjacent sections were constructed, completing I-5 in the City of San Diego.
The San Gabriel Mountains have been subject to quite a bit of deformation in their past. Some of which is still ongoing, such as the movements along the Sierra Madre and San Andreas Faults. Here, near Mt Wilson, the rocks exhibit multiple instances of deformation. The white vein is mostly composed of quartz, which has been offset by multiple faults. Slickensides can be seen as the reddish areas on the right side of the photo. The surrounding materials are complex metamorphic rocks.
Near the southern end of the Salton Sea in the Imperial Valley, you can find some very interesting geological features. Mud volcanoes, slowly “erupting” a fine muddy ooze, are some of the evidence of the extreme heat not far below the surface here. Gases, usually carbon dioxide, also emanate from the ground here. These mud volcanoes are more active in winter and spring, when groundwater is a little higher and the surface temperatures are a bit lower. I highly recommend a visit sometime.
Looking toward South Mount Hawkins in the West Fork San Gabriel Canyon from State 39. This road was planned to be improved but landslides prevented this work from being completed. In the case of this area, almost all of the low lying areas not covered in snow are landslides in one form or another. Even Crystal Lake, where this roadway is headed, exists because of landslides.