The route is about 6 miles with at least 1600 feet elevation gain round trip. In good weather it should present no major difficulties except that you do need to pay attention to your directions because you cannot see landmarks for the first two-thirds of the route.
The route starts at Buckhorn Lakes. It varies slightly from the route described in Mitchler and Covill's Hiking Colorado's Summits
. It requires less bushwhacking, but is longer since it follows a meandering ATV trail part of the way.
Follow the driving directions on the main page to Buckhorn Lakes at 9,745' elevation. Measure 1.3 miles past the entrance sign, to a side road that heads south. Both the main road and side road are steep at this point. The elevation at this juncture is 10,050'. There is room to park at the bottom of the hill just below this point.
Follow the road through the woods, with some up and down, past many large mud puddles. The road heads generally south, parallel to the Cimarron Ridge. Above you are the Sawtooth Rocks, which you can rarely see through the trees. At about 1 mile the road turns east, which is exactly what you want. Follow the road east, then briefly back to the north before it switches back once more and terminates at about 1.5 miles. At the end of the road, find a 2-track ATV trail heading steeply up to the east again. You have gained very little elevation to this point.
The ATV trail meanders through the forest, but eventually takes you through a broad saddle below the Sawtooth Rocks. Alternatively, you could make your own trail through the dense forest and possibly save yourself some mileage. The ATV trail goes up and down a lot and you never know exactly where you are because the visibility is about 50-100 yards. The ATV track does not go to the summit; it continues east. When it starts going consistently down, then it is time to strike out on your own. Your elevation here is about 10,400 feet.
Leave the comforts of the trail, and bushwhack up the east side of the north ridge. Always gain elevation, but there is no hurry to regain the ridge crest, such as it is. Gain the ridge crest at or before 11,200' and catch a good view of Storm King's vertical west face. Continue along the ridge to the summit of Storm King. The steepest climbing is just before the summit.
From Storm King, the terrain eases considerably. Bear slightly to the left, and enjoy your stroll through the forest, for the last half mile to the summit of Castle Rock. You will recognize the summit by the presence of a television broadcast tower and a small building.
On your return, retrace your steps and catch the ATV trail at any point along the east side of the ridge near the broad, uneven saddle.
Orientation devices: compass, altimeter, and topo map. Or GPS for the navigationally challenged. After the first snow and through June, consider bringing snow shoes. Snow cover was 70% and knee deep, on September 30, 2006. The area can be very wet any time of year.