Classic Round Valley Loop
The Round Valley Trail is a nicely built singletrack trail just northeast of Park City. This buff trail climbs over a ridge, dips through Round Valley, then runs over another ridge to drop back down to the valley floor 5.7 miles later. The official Round Valley Loop adds some broad improved trail (McLeod Creek and Rail Trail) and a couple of city streets to create a popular 14.3-mile loop. The trail is well-marked with signposts. Despite the 14-mile distance, the Round Valley Loop is an easy ride. There's 600 vertical feet of climbing. Top altitude is 7075 ft.
Riding notes, classic loop from Quinn's:
0.0  Exit parking, turn right onto paved path
N40 40.757 W111 28.225
0.1  L along Ice Arena parking to 4-way intersection
Rambler is ST on far side, uphill right
N40 40.889 W111 28.318
0.4  R to stay on Rambler
N40 41.096 W111 28.415
0.6  Keep R (L = Kari's)
N40 41.199 W111 28.420
1.0  R downhill (trails rejoin)
N40 41.530 W111 28.408
1.2  Straight (uphill, cross Ramble On)
N40 41.630 W111 28.450
1.5  Straight (L = Kari's)
N40 41.781 W111 28.624
1.8  Straight (L = High Side)
N40 41.801 W111 28.754
2.2  Straight (L=Nowhere Elks, R=Rusty Shovel)
N40 41.724 W111 29.018
2.9  Keep R (L = Seventy 101)
N40 41.706 W111 29.271
3.6  Keep L (R = Ramble On)
N40 42.003 W111 29.501
3.7  Straight across Round Valley Express
N40 42.051 W111 29.497
Veer L and join connector in 100 feet
3.8   Keep L on ST (R = Rademan)
4.2   Straight across Rademan Ridge
N40 41.993 W111 29.907
Stay on main trail on descent
5.4   Hard R (L = back to Round Valley)
N40 41.946 W111 30.354
5.7   TH, L on road N40 42.062 W111 30.444
6.0   Road turns R N40 41.860 W111 30.467
6.6   L onto cindered path (Farm Trail)
N40 41.854 W111 31.232
7.7   Keep straight onto McCleod
100 feet then fork L
N40 41.638 W111 32.162
8.7   Join paved trail, keep straight
N40 40.939 W111 32.033
10.9 At street, L on sidewalk
N40 39.733 W111 30.632
trail is sidewalk across next street
12.1 Crosswalk, then L and descend to underpass
N40 40.100 W111 29.528
12.6 L on Rail Trail N40 40.043 W111 29.008
13.7 L on road N40 40.434 W111 27.870
13.8 R on paved trail N40 40.441 W111 28.035
14.2 Cross road, then L uphill past bathrooms
14.3 Back at Quinn's parking
Getting there, Loop Trailhead on the Rail Trail: Southbound on Park City's Park Avenue, turn left onto Kearns Blvd., as though you were heading to US 40. About 1/4 mile later, turn right on Bonanza Drive. At the "Rail Trail" sign about 200 feet later, turn left onto Prospector Avenue, then right into the parking lot for the Rail Trail. The trail is at the far (south) end of the parking lot. N 40° 39.684' W 111° 29.894'
Quinn's TH near US-40: On I-80, turn south at Silver Creek Junction (towards Heber). At the second exit (about 3 miles later) turn right towards Park City on Kearns Blvd (Highway 248). Less than 1/4 mile from the exit, turn right at the light onto Round Valley Drive. Quickly turn left onto Gilmor Way. Follow it around (pass the first parking lot) and veer north. You'll pass parking lots on your right. Head to the top of the parking area. Quinn's TH is across Gilmor Way. Rambler can be reached by heading toward the Ice Arena building.