149 Borrego Springs. 73 Miles, 6650 ft el, 91 ft/mi

0.0 L Via Vera Cruz
0.5 L Grand
0.6 R Las Posas
1.0 R Mission
2.7 L Vineyard
4.0 R Mulberry
4.3 L Borden
5.6 = El Norte
5.9 L Country Club
6.0 R Country Club
8.3 R Ash
9.8 L El Norte
11.3 = Citrus
11.8 L Washington
12.8 L Valley
13.6 R Lake Wohlford
21.5 R Valley Center
26.6 R Pala Hwy. 76
46.3 L Hwy. 79
50.5 R San Felipe S52
55.1 L Montezuma Valley
72.5 R Palm Canyon
74.0 Borrego Springs

This is a one-way route, so double it to 146 miles for an out-and-back.
If you return, the Montezuma East grade is a category 1 climb challenge! It is 12 mi / 19.6 Km long, elevation gain 3527 ft, average grade 5.6%.