View northbound a few miles into the ride. You'll spot a few huge homes on the hills above the trail. Photos by Bruce, August 16, 2010.
The Princess Di trail is a singletrack trail that hugs the hillside east of Promontory. The
track is narrow, with some areas of loose volcanic rock that create tricky traction on the
many tight switchback turns. This makes the trail "expert" in technical requirement, although
intermediates can ride it by dismounting on most of the turns.
Princess Di can be reached directly from the bottom (northern) end by taking the Promontory/Tollgate
Canyon I-80 exit. But most riders do the ride as a loop starting with the paved Three Mile
Canyon trail, then finishing with 4 miles on the Rail Trail. For this review, we'll assume
you're doing the counterclockwise loop starting from the Rail Trail Promontory trailhead off
Just getting started. The Three Mile Canyon paved trail has a gentle slope, climbing 400 vertical feet in 2.4 miles, then descending 100 feet over 0.6 miles before you hit the singletrack Princess Di trail.
From the Three Mile Canyon Trail, there are views west to Parley's Summit and south to Deer Valley. After cresting the hill, you'll be above a little golf course stuffed into the little canyon.
Princess Di itself is 7.5 miles in length, with the total loop ride being 14.5 miles. The 7
miles you'll spend on the paved Three Mile Canyon and cindered Rail Trail are pretty easy.
Still, the ride is a moderately strenuous trip due to the climbing on Princess Di.Trailhead parking is at 6500 feet elevation. Top altitude is 7300 at the ridgeline 10 miles
into the ride, bottom 6300 at the Rail Trail. You'll gain, lose, and regain altitude for about
1800 total feet of climbing.
Start at the Promontory Trailhead for the Rail Trail (see below). Head out of the parking lot
to the street, cross the road, and turn left on the paved path. Keep on the paved bike path,
ignoring the many side trails and confusing signs. Climb the hill for 2.4 miles. The paved
trail follows the road for the first mile, then veers out into the brush of the hillside, but
returns to the road at the top.
Heading downhill after crossing the ridge. The Princess Di trail is just a couple of wiggles away.
Entry into Princess Di. The trail is very well marked with carsonite signposts. If you find yourself confused, look around for a post, or check the dirt for tire tracks.
At the crest of the hill, the paved path will turn away from the roadway and begin descending.
You'll drop 100 feet of the 400 you gained since the trailhead. At exactly mile 3.0, the trail
makes a hairpin turn to the right (as of 2010, the pavement ended here). The Princess Di trail
forks north (left) at the apex of this turn.
Princess Di contours around the east side of the Promontory mountain, keeping just below the
easternmost homes of the development. The trail will go in and out of several drainages, gently
gaining and losing altitude. You'll hit quite a few very tight and loose switchbacks on this
side of the mountain. But if you hate switchbacks, you haven't seen anything yet. Just wait.
The trail skirts an outcrop of volcanic rock, a mix of pumice and ash.
View east toward Rockport Reservoir.
On south slopes, the trail base is fairly smooth overall, but with scattered loose sharp volcanic
chunks. These make climbing around a sharp uphill switchback more interesting. Southern slopes
are usually bitterbrush and sage with occasional stands of gambel oak.
On north-facing slopes, the trail is hardpack dirt, with a few petrified ruts left over from
early season. There are occasional sections of teeth-rattling horse-hoof postholes. The north
slopes have thicker brush and oak, with groves of aspen, choke cherry, and maple.The last long climb on the singletrack gains 400 feet over about 1.5 miles, putting you on
top of the ridge at 7300 feet. To the west are views over Park City and Jeremy Ranch. To the
east, Rockport Reservoir sits in front of the Uintah Mountain foothills.
Typical trail section on a north-facing slope. Thick low shrubs such as potentilla mix with sage between small stands of aspen, maple, or oak. There's occasional elderberry, serviceberry, or chokecherry.
View west from the top. The light stripe at mid-left is the end of the subdivision road. The continuing singletrack is across on the other side.
At the top, head for the end of the roadway in front of you. Look for the trail post on the
other side of the road, about 100 feet before the end. Hit the singletrack and begin your descent.
You'll be dropping 1000 vertical feet over 4 miles and countless switchbacks. Fun stuff. Great
ride if you've got the handling skills to roll the turns quickly.
The trail grade on the downhill is usually fairly mellow and consistent. But the track is narrow
enough that you'll have little temptation to "fly" and your descent will be interrupted regularly
by very tight tricky turns.Near the bottom, there's a long straight downhill as you and the Promontory Road follow a small
creek down toward I-80.
One of the few groves of larger trees, as the trail becomes cool and shady under the maples.
I-80, with the Rail Trail between the lanes.
The final bit of singletrack is a steep section that clings to a cliff-like washed-out sidehill.
Just ride. It's easier to roll down on the bike than to walk it. The trail ends where Promontory
Road hits the freeway exit.Turn right and cross I-80. Notice the little tree-lined pit to your right. Hike down into the
creek (dry in August), turn right, and go through the tunnel under the southbound lane. In
between freeway lanes, you'll find the Rail Trail. Turn right and ride uphill 4 miles back
to the trailhead.
0.0 Back to road N40 43.475 W111 28.309Cross road, L on paved trailBeginpaved trail0.3 Keep straight on paved trail at all crossingsN40 43.449 W111 28.082(R = to South Canyon Trail)2.4 Top of ridge, begin to descend3.0 L on singletrack (end of pavement 2010)N40 44.537 W111 26.103Beginsingletrack7.2 Top of ridge, angle L across road to STN40 46.140 W111 26.772
Clattering through the tunnel under the freeway, with a bridge on the Rail Trail waiting on the other side.
On the Rail Trail southbound, between the lanes of I-80. Not as obnoxiously noisy as you'd think.
7.6 Cross paved road9.4 Drop R on ST as you hit clearing with bldgN40 46.684 W111 27.39110.5 Plunge down to road, turn R and go over I-80N40 46.512 W111 28.066Immediately after freeway, drop R into "hole"N40 46.530 W111 28.161R into drain tunnel, go under southbound landR onin between lanes of freeway14.5 L into parking area
Take I-80 eastbound out of Salt Lake City and cross Parley's Summit. Pass the Park City exit,
then a couple of miles later, take US-40 south at Silver Creek Junction. In 1 miles, exit at
Silver Summit. Turn L (east). Follow the road as it veers north. At 0.8 miles after leaving
US-40, turn right on Promontory Ranch Road. Continue about 1/2 mile. Just after crossing the
Rail Trail, turn left into a paved parking area with a "Promontory" sign. Begin the ride by
heading for the paved trail across the road from parking.Outhouse at trailhead. None at trailhead. Convenience store 1/2 mile away. None in immediate
area. Nearby at Rockport, Echo, or Jordanelle Reservoirs. Multiple shops with rentals and repairs
in Park City.