September 14, 2018
This seems to be a pretty old description, so here's an update...
I wouldn't call this a destination trail system, but worth checking out if you live in Boise, and very nice to have as your backyard trails if you happen to live in Hidden Springs.
REDTAIL is an out and back, up a nicely crafted trail that gets you about 900' of climbing in 3 miles, to a grassy summit with views. Downhill has good flow.
BITTERBRUSH is a mile-long, mostly traversing connector from Redtail to Chukar Buttetrail, which will take you east out to Sweet Connie, and the rest of the greater Boise trail system.
CURRANT CREEK makes a 3/4 circle about 3 miles long, mostly up a drainage with cottonwoods, with moderate rolling climbs and descents. You will be around and between some newer residential streets and cul-De-sacs, and cross paved roads twice; look for signposts to keep you on track. The eastern terminus of this trail is Chukar Butte trail, about a mile higher than where BITTERBRUSH would put you. This is my preferred way to start a longer ride up Chukar Butte.
CARTWRIGHT RIDGE is a newer trail, about 3 1/4 miles long, on the back side of the Hidden Springs Valley, and not connected to the above trails (without riding a mile through the neighborhood). This mostly traversing trail will bring you to within a 1/4 mile of the Polecat TH, allowing you to make some long (15 - 25 mile) loops from Hidden Springs.
My favorite 2 hr, 18 mile loop is Currant Cr - Chukar Butte - Sweet Connie - Peggy's - Cartwright Ridge. Gets you about 2500' of climbing, 90% singletrack, and very little trail traffic (compared to Camel's Back or Military Reserve areas!).
These trails are all mapped at MTB Project.