You don't even need to leave the lower 48....
There are fares MSP--SJC or MSP--SFO on CO that allow routing MSP--CLE--IAH--SFO/SJC that will put you over 3800. Fares start at $238 plus tax for travel noon Mon--noon Thurs or Sat PM, with a Sat. night stay. The fare is $298 for other times. Average these, to leave Sat. and return Sun.
I found availability for the following:
Sat. Dec. 14 lv. MSP 1:15pm, lv. CLE 5:45pm, arr. SFO 8pm
Sun. Dec. 15 lv. SFO 12:50am (= satisfied Sat. night stay; no hotel cost), lv. IAH 7:45am, lv. EWR 3:20pm, arr. MSP 5:32pm
Mileage: MSP-CLE 621, CLE-SFO 2157, SFO-IAH 1641, IAH--EWR 1415, EWR--MSP 1017, total 6851 miles.
Fare: $300.50 after lots of tax.
This can easily be booked on continental.com for a few extra miles.... and since all flights are CO operated, I wonder if there may be an extra bonus out there someplace.... I haven't been on CO metal for so long, I've lost touch.
Good luck.