The distance on this is probably more like 4.3, but it's a great loop over some challenging terrain, decent hills for the midwest, and scenic with Lake McBride and the Coralville Resevoir visible on your right for most of the loop.
There is a potable well water spigot at the Bluestem shelter. There's one tricky turn to watch out for. After the spillway, and just after dropping down into a gulley and then on the climb back out, there's a right turn you'll need to look hard for because it's relatively inconspicuous. It's about halfway up the steep ridge that climbs out of the gulley. If you get to the top of that ridge, you've missed the turn.
This hike starts at the BlueStem shelter of McBride Recreation area. Cross the road heading down toward the sailboat club and turn left onto the Field Campus Trail
. Stay on this trail all the way to the spillway where Lake McBride pours into the Coralville Resevoir. There are a couple trail intersections along this stretch, but if you bear right at all times, you'll stay on the route.
When you reach the spillway, after taking in the sights, head south on the trail that's now paralleling the Res shoreline. Turn right about half way up the steep ridge that climbs out of the first drainage. Stay on this trail as it follows the contour of the shoreline until it ends in a T-intersection with another trail. Take a left here away from the shoreline. This trail will be crossed by a wide grass path; go straight across this and back into a small low-lying area, then back out to another wide doubletrack.
Take a right on this doubletrack. You can add a mile and a half by staying on this trail down to a little peninsula, but the route I take here turns left after about a quarter mile at the Blue Bird trailhead. You'll skirt around the woods to your left, with an open prairie on your right. Bear left here and turn left back into the woods, with the Reservoir back on your right. You'll come down to a low flood plain. This area could be underwater depending on the level of the Res, so where the trail forks, you can go right or straight based on the conditions. (Stop down by the water and look across to catch a glimpse of one of the huge SETI telescopes sticking out above the trees perpetually searching for extra terrestrial intelligence).
The trail leads back up the opposite side of the drainage and will come out at a dirt/gravel road. Cross the road to the Hawk/Ravine Trail, and follow it down and steep technical descent, followed by an equally steep ascent. At the top of the opposite side of the ravine, you'll come out at a gravel parking lot. Bear right, staying on the grass and then turn right down the gravel road leading back from the parking lot. About 50 feet on, turn left onto a grass trail, and bear left as it rounds a couple curves and then heads you straight back east toward the Bluestem shelter. There's about .75 miles to go, and a few intersecting trails, but if you more or less bear right without taking any hard right turns, you'll come back out into a prairie and see the Blue Stem shelter ahead of you and your vehicle waiting.