Thom02099 has a good list of place you can go. If you'll be there all summer, Salida is nicely situated to go to a lot of great places.
Been years since I've done much fishing, but some ideas to explore:
The reservoirs in South Park are known for big fish. Was with a buddy when he caught a 27" rainbow out of Elevenmile. Big fish also in Spinney and Antero. All of these are out away from the trees, so not much protection from the wind. I've heard there's good stream fishing on the Platte in the canyon below Elevenmile.
If you're looking for some quick evening after work getaways, try Cottonwood Lake and O'Haver Lake. Mostly stockers in O'Haver Lake. Cottonwood Lake is deeper and holds some decent sized fish. Also, you can wade upstream into the willows and find some nice ponds along the stream.
Mirror Lake on the other side of Tincup Pass is a beautiful place to fish. Just stockers, but the scenery will blow you away. The streams above Tincup have some beaver ponds that should be interesting but you might have to bushwhack a little to get to the good stuff. Further downstream you get to Taylor Park. The reservoir there has some interest places where the streams feed in. Take the road up the Taylor River and try your luck along there.
I've often found the most fun fishing is in some of the high mountain lakes that you have to hike into. It can be real hit or miss. Some lakes seem absolutely dead one evening, then the next morning there's a feeding frenzy. I try to steer clear of lakes with mines right above them as often the heavy metals have killed the vegetation and fish in the lake.
You'll have plenty of time to explore places to fish. Get on Google and pull up the satellite images of the area. Then locate beaver ponds a little off the road where people can't just drive up and drop a line in. For instance when we've driven up the Hagerman Pass road above Turquoise Lake I've looked down at Busk Creek and all the little ponds and slack water areas and think that might be some place to explore. But as I said, I rarely fish anymore.
For other things to do, check out
this link. There's river rafting for all abilities and ages. Worth doing and easy section once just to see what it's all about. A 4x4 does help explore a lot of this area. But many ghost towns can be reached with a normal car. St. Elmo is a good example. We find downtown Salida a great little town. In the summer, they have all sorts of concerts and events in the park down by the river. Spend too much time there and you may never leave. It was one of our final picks of places to move to before we ended up in Glenwood. The ArtWalk in late June is a great little festival of local artists in a great little town.
BTW, if you mountain bike or want to learn, this is a great place to do it. Even if you don't mountain bike, Salida is very bike friendly -- locals go to the park, go shopping, and go to the restaurants on their bicycles.
Ken & Allison
2 Camping Cats (1 diabetic)
1996 4Runner, TRD Supercharger, Edelbrock headers
2007 Fleetwood Arcadia, Honda EU2000i
4 mountain bikes, 1 canoe, 4 tents, 8 sleeping bags, 2 backpacks
(You get the idea!)