Yeah you can, but not from ANY other school. I know PSU credits transfer and I think L & C might too, but check with your adviser when you meet with them during O-Week. If you're going to take your science course elsewhere, I'd recommend taking it during the summer.
The individual course must be approved as well, covering the same material as Reed's (DD found this, getting chemistry approved but not her first choice, physics, at SCU). I agree, only summer makes sense.
With the exception of PSU (and possibly L&C, but I am not sure), you must talk to the head of the department for which you wish to fulfill your science credit.