Here are some results (sorted by mileage):
- Seatte / Mt Hood / La Pine / Summer Lake / Alturas / Cedarville / Gerlach: 662 miles, 20120 ft gain, (-16357 ft drop), total of 7 crests; longest climbs: Mt Hood, Summer Lake ascent, Cedar Pass
Seatte / Mt Hood / La Pine / Klamath Falls / Alturas / Cedarville / Gerlach: 669 miles, 19817 ft gain, (-16052 ft drop), total of 6 crests; longest climbs: Mt Hood, Klamath Lake descent, Cedar Pass
Seattle / I-5 / Eugene / Klamath Falls / Alturas / Cedarville / Gerlach: 675 miles, 18668 ft gain, (-14903 ft drop), total of 5 crests; longest climbs: Willamette Pass, Klamath Lake descent, Cedar Pass
Seattle / Yakima / La Pine / Summer Lake / Alturas / Cedarville / Gerlach: 694 miles, 26547 ft gain, (-22785 ft drop), total of 10 crests; longest climbs: Snoqualmie Pass, Yakima Vally, Columbia Gorge, Summer Lake ascent, Cedar Pass
Seattle / I-5 / Eugene / La Pine / Summer Lake / Alturas / Cedarville / Gerlach: 698 miles, 18971 ft gain, (-15208 ft drop), total of 6 crests; longest climbs: Willamette Pass, Summer Lake ascent, Cedar Pass
Seattle / Yakima / La Pine / Klamath Falls / Alturas / Cedarville / Gerlach: 701 miles, 26244 ft gain, (-22480 ft drop), total of 9 crests; longest climbs: Snoqualmie Pass, Yakima Vally, Columbia Gorge, Klamath Lake descent, Cedar Pass
Seattle / I-5 / Eugene / Klamath Falls / Susanville / Reno / Pyramid Lk / Gerlach: 816 miles, 22531 ft gain, (-18765 ft drop), total of 5 crests; longest climbs: Willamette Pass, Pass near Hayden Hill-Silva Refuge, Pyramid Lk ascent
Seatte / Mt Hood / La Pine / Summer Lake / Alturas / Susanville / Reno / Pyramid Lk / Gerlach: 842 miles, 23750 ft gain, (-19988 ft drop), total of 8 crests; longest climbs: Mt Hood, Summer Lake ascent, Tule Mt Pass, Pyramid Lk ascent
Seattle / Yakima / La Pine / Summer Lake / Alturas / Susanville / Reno / Pyramid Lk / Gerlach: 874 miles, 30177 ft gain, (-26416 ft drop), total of 11 crests; longest climbs: Snoqualmie Pass, Yakima Vally, Columbia Gorge, Summer Lake ascent, Tule Mt Pass, Pyramid Lk ascent
Seattle / I-5 / Eugene / La Pine / Summer Lake / Alturas / Susanville / Reno / Pyramid Lk / Gerlach: 878 miles, 22601 ft gain, (-18839 ft drop), total of 7 crests; longest climbs: Willamette Pass, Summer Lake ascent, Tule Mt Pass, Pyramid Lk asce
Seattle / I-5 / Eugene / I-5 / Sacramento / Lk Tahoe / Reno / Pyramid Lk / Gerlach: 996 miles, 29677 ft gain, (-25913 ft drop), total of 4 crests; longest climbs: Siskiyou Pass, Mt Shasta, long and steady Sierra Nevada ascent, Pyramid Lk ascent
For least altitude gain: Seattle / Eugene / Klamath Falls / Cedarville / Gerlach: 675 miles, 18668 ft gain, (also pretty tame in the reverse). Willamette pass is a long haul, but not too steep. Cedar Pass is steep, but the stretch over 2% is about 6 miles (cool down at the top). This route does have the steepest slope (a stretch of Willamette and Cedar both hit 6.9%), so think of this as as the
fuel saving path.
Least slope path: Seattle / Sacramento / Reno / Gerlach: 996 miles, total of 4 crests. For an extra 320 miles you can take the long steady climb following the people from SF. Hardly seems worth it when the Sierra climb is 6.4% in spots and very long.
Good alternate for slope: Seatte / Mt Hood / Klamath Falls / Cedarville / Gerlach: 669 miles. Mt Hood is easier than Willamette Pass, but you still gotta hit the 6 mile climb on Cedarville. Low traffic on the pass still makes this one a winner for me. (Plus I like the cheap gas in Sandy, OR on the way to Mt. Hood!!)