The Surprise Trailhead is located 25 miles northwest of Silverthorne, CO in the Eagles Nest Wilderness Area. It provides access to a string of subalpine lakes of varying distance and difficulty, prized for their backcountry camping, fishing, and solitude.

Upper Cataract Lake and Cat Lake are connected by an outlet stream in the shadow of Eagles Nest Peak (13,091'), the eponymous summit of this wilderness area. Visitors will enjoy diverse forests, prolific wildflowers and lengthy shorelines to explore at Upper Cataract Lake and Cat Lake:

The Surprise Trail rises steadily through aspen-studded hillsides on a S-SE heading to the Eagles Nest Wilderness Boundary (.27 miles : 8,725'). Wildflowers are simply brilliant on this initial stretch, but note that you'll encounter some of the hike's steepest sections on the first two miles. Look for bear, elk, and moose in grassy clearings along the way.

The trail passes through a large aspen grove (.8 miles) to a stream crossing on a makeshift bridge (1.0 mile : 9,135'). Once over it steepens beside a long, slender meadow into a predominantly spruce-fir forest. Though badly affected by beetle kill, deadfall has cleared space for new growth and verdant ground cover.

The steep, steady climb continues over a second creek (2.4 miles : 9,905') and eases to the Gore Range Trail split (2.7 miles : 9,953'). Follow signs to Surprise Lake (2.9 miles : 10,044'). Surprise Lake is partially concealed by thick forest and marshy bands between the trail and north shore. Dora Mountain (12,292') reflects in this small, lily covered lake.

The trail keeps west, bisected by several small streams to the Upper Cataract Trail split (3.45 miles : 10,387'). Veer SW on the Upper Cataract Trail into a markedly healthier forest, and arguably the hike's most pleasant stretch. The trail rises gently and shifts frequently to its highest point (5.0 miles : 10,890'), where it drops to a sprawling talus field at the base of Eagles Nest Peak (5.15 miles : 10,825').

The trail twists around the talus field with great views of Cat Lake down to the Upper Cataract Lake split (5.35 miles : 10,725'). A short unmaintained spur is intuitively followed to the northeast shore of Upper Cataract Lake (5.45 miles : 10,744'). Upper Cataract Lake is notably large and contoured, ringed with pockets of timber, open space, and marsh.

To reach Cat Lake, backtrack to the Upper Cataract Lake split and continue.1 mile west to the access spur on the right. Anticipate this split, as the sign is fairly hidden. The spur drops steeply to the south shore of Cat Lake (5.6 miles : 10,395'), which is thickly wooded but easy to explore.