The 80 km Shasta Valley Loop (this is Andreas' name, nothing official) starts in Weed. You take Edgewood Rd North parallel to Interstate 5 which you pass to turn right into Old Hwy 99.
My Shasta from Hwy 99 in the morning light
My Shasta from Hwy 99 with cloud
Shasta Valley at sun rise
View over Shasta Valley
Take Hwy 99 North. In Gazelle, you have the option to turn left into Gazelle Callahan Rd and then right into Old Westside Rd. Eventually you get to Cut-off which you take East.
Mt Shasta from Cut-off
Mt Shasta, Black Butte and Mt Eddy from Shasta Valley
Cut-off is a wide road with a wide shoulder and relatively light traffic. It's a long 2% uphill. You gain over 400 m in about 20 km. The road ends at Hwy 97 which you take West back to Weed. The highway has a shoulder as wide a lane and you can have a fun downhill.
Herd Peak from Hwy 97
The Eddys from Hwy 97