Heading down Baldwin Loop is a singletrack trail, however about 50% back up is a fire road closed to motor vehicles.
From The top of Baldwin Loop and Enchanted Loop
, you start with a fun rolling descent through grasslands. The mellow drop steepens, and you'll soon find yourself picking up speed. Luckily, there is a wide-open sight line which makes the high speeds feel comfortable. The max grade tops out at 17%, but the descent generally doesn't get much steeper than 14%.
Before reaching the bottom, you cross a cool drainage which provides nice shade and cool weather which the rest of the trail is pretty exposed. Enjoy the reprieve from the heat, and get ready for your climb back up.
The ascent is somewhat grueling, but the Baldwin loop is a must in the eastern part of the park. This trail can also be linked up with the Ohlone Bluff trail for a more mellow flat pedal back to the parking area.