It might be a little out of your way, but I can highly recommend Jeff Stieb. Last I knew he was working/directing in Broomfield at Synapse Physical Therapy. I know he was there a year ago anyway. I have a couple friends who've worked with him to rehab after shoulder surgery. I had a bad elbow injury several years back and like with you, it was a major concern getting back my ROM. I spent so much time in PT that I had a chance to sample a number of physical therapists and Jeff was by far the best. He has a special interest in upper extremity problems, loves to get hands on, has a super positive attitude, lots of energy, and has years of experience. We tracked the metrics on my elbow ROM carefully and the bottom line for me was that after a session with him, my ROM increased (albeit a temporary effect) more with him than anybody else. I didn't need to measure it, I could feel a significant difference. I also spent countless hours a day stretching on my own of course.
Anyway, good luck. You can probably find plenty of qualified therapists in the Boulder area, but you won't go wrong with Stieb.