I wouldnt cliff jump in poudre canyon...not enough deep ares plus the water is moving fast this year...there is one spot at the south dam of horsetooth reservoir if you are ever in the fort collins area
St. Marys Glacier has some dope spots if anyone was curious me and LO_GO hit it up last weekend you can ski the glacier and its 2 jank jibs then go jump off some cliffs pretty legit were making another trip out there next week
there is some great jumping up the poudre a little at seimens(sp?) resivour. I went last week it was dope. good like 45 footer probably and some smaller ones. Also there is one of the best rope swings i have been on. However, I shot the rope swing wrong once and went straight into a rock... fuckin gnarly!