The hot, dry winds that blow down from the deserts in autumn and winter, fanning wildfires across Southern California, are called the Santa Anas, and they are often said to take their name from the Santa Ana Canyon, where they funnel through the hills towards the coast. This stop lies right at the mouth of that canyon, near Yorba Linda and Corona, where the Santa Ana River cuts through the hills between Orange County and the Inland Empire.
The SR-91 freeway runs through the canyon, and it is one of the most congested roads in America, with traffic crawling in both directions at rush hour. Toll lanes offer a faster but expensive alternative, and motorcycles may have different rules on them, so check before you go.
There is no good swimming here. The Santa Ana River is a channel of concrete and sand, dry for much of the year, and the reservoirs nearby are not for bathing. The nearest real swimming is the ocean, about an hour's ride west, or Lake Elsinore, to the south-east.
Chino Hills State Park, to the north, is a wild area of rolling hills, oak woodland and grassland, with trails and views over the valleys. It is a surprising escape from the suburbs.
Coming back from Death Valley, the contrast is total. A day ago you were in the lowest, hottest, emptiest place in North America; now you are inching through one of its busiest freeway canyons, surrounded by commuters. Lane splitting helps, carefully done, but patience helps more.
Corona and Yorba Linda have fuel and every chain restaurant known to man. Yorba Linda also holds the birthplace and library of Richard Nixon, a small farmhouse his father built, which is an odd and interesting stop if you arrive with daylight and curiosity to spare. When the Santa Anas are blowing, ride with extra care: gusts in the canyon are strong, and fire crews may close roads with no warning.