Don,
Don't know about Rock Springs BUT last year I was hunting Lopes north of Green River and brought my Lope down to someone who was highly rated. Go to Green River and find the following place for a very good and fast turn around if need be.
R&B MEATS
515 E. 2nd North Street
Green River
307-875-2556
In fact, just had some Lope steaks tonight for dinner from last year, excellent tasting and tender.
If I get the chance to hunt around that area again, I will be making the drive there to have it taken care of.
Brian