Well, between Temecula and Corona, you will have to travel on Old Temescal Canyon Road after you wind your way through the Lake Elsinore valley. It starts after Main, north of Lake Elsinore in Aberhill (it may be called Lake St., depending on the map). It's a nice, although narrow route. I take Scouts on this road for the Historic Cycling Award.

Be aware that Temescal Canyon Road is closed between Wierick and Cajalco roads. I'm not sure how to get around this, short of going on the freeway for a couple miles. I will try to find a route and get back to you.

Also, there is a lot of freeway construction between Victorville and Barstow.

Carry A LOT of water when cycling in the desert. Try to avoid long rides out here in the summer, you just can't carry enough water. It will easily be over 100F for most of the day. Your daily water requirement will approach 15 liters.