The access road to Thirtymile Campground and Rio Grande Reservoir turns off from SH149 either 20.5 miles west from Creede or 32 miles south from Lake City. The turnoff is marked by a road sign. From Lake City, you'll have to drive over Slumgullion Pass and Spring Creek Pass. This remote access for Rio Grande Pyramid and other 13er summits nearby makes these peaks some of the most distant for climbers coming from both the eastern and western slopes of Colorado, requiring multiple hours of driving.
Watch for FR520/CR18 turning off to the west side of highway 149. Initially, the road is paved as it drops down to a small reservoir where it turns NNW and turns to graded dirt. Shortly after that, stay left at an intersection. For the most part, stay on the most well-travelled road to get to Rio Grande Reservoir. Most major intersections are signed. So at about 3.5 miles from the highway, stay left and head south. In the next mile you'll come to Road Canyon Reservoir #1 where there is a National Forest Fee campground along the side of the road at the south end of the reservoir with a vault toilet and a half dozen sites or so. Continue on past the River Hill CG another 3.4 miles SW and then you'll arrive at the Thirtymile CG at 10.8 miles from the highway. Both Thirtymile and River Hill campgrounds are also Forest Service, fee campgrounds with vault toilets, tables, firerings and potable water. Sites can be reserved at www.recreation.gov.
To access the campground, you'll need to drive south across the river on a good bridge. There's a grassy/dirt parking area intended for backpackers and hikers on the north side of the main road into the campground. For the actual trailhead, you'll need to walk south from the parking area, crossing the other side of the road that loops through and then walk a little farther south from there. The trailhead serves as access for both Squaw Creek and Weminuche Creek. There is a kiosk there for registering your activity.
Camping sites at Thirtymile CG and River Hill CG are available and can even be reserved online at www.recreation.gov. There's also another campground at the far west end of Rio Grande Reservoir called "Lost Trail CG," but you would have to drive back from there to access the Weminuche Creek Trail or the Squaw Creek Trail. On the drive in from the highway, there are not very many primitive sites that show. Several roads that turn off the main road lead to private property.
The trailhead for the Weminuche Pass trail is shared by the trailhead for Squaw Creek. There is a kiosk there with the usual Forest Service information and a box to register your hike or backpack. This trailhead is located on the south side of the campground, across the loop, campsite road and more toward the west end of the campground. The trailhead coordinates are for the actual trailhead and not some other spot in the campground. The correct trail number is 818.
When it comes to backpacking, approach hikes, this is one of the easier. A little over five miles of walking with only 1,325 feet of elevation gain places you in great position for five 13er summits that can be done from a very nice base camp. Our last trip here in 2008 still did not show much beetle kill damage to the forest, however, the Squaw Creek trail a little farther east showed at least 60% kill of the forest. We recently re-visited this trail I 2017 and found however, that the beetle kill has hit the Weminuche drainage as well with up to 80% kill in some areas.
For the Weminuche Pass trail, walk west from the kiosk on an old roadbed that shortly becomes trail which stays above the south shore of the reservoir, gaining little elevation for the first 1.25 mile. After that, in the next half mile it gains a few hundred feet and then makes a pronounced turn south, away from the reservoir. At just under 2 miles, you'll come to a major crossing of Weminuche Creek as it cascades down from above. There is a sturdy footbridge here and the location makes a great place for your first break and to take some photos.
Beyond the creek crossing, the trail first heads up along and above the creek on the west side, does a brief switchback north to gain some elevation, then returns to a more southwesterly direction. Not far past the stream crossing, you'll leave the denser forest behind. Much of the trail now follows along the edge of the forest with views of the open, grassy meadow that surrounds Weminuche Creek. The walking gradient is gentle. There is a campsite located on the east side of the trail perhaps a mile up from the bridge. The last mile to the pass, the trail enters more trees. You'll begin to see some possible campsites, but our preferred camping location has been just north of the pass, and just after you have crossed a stream coming in from the west that is a major tributary of Weminuche Creek. There will also be a trail branching off to the west near here. On the east side of the main trail, there are some clusters of trees and several flat places that offer excellent camping with the shelter of the tall trees. This was a very pleasant backcountry campsite, however our 2017 visit here showed that the trees in this location are now mostly dead. Lower growing vegetation is starting to fill in obscuring some of the flatter camp spots, but there are still two very good campsite locations. The tributary stream nearby offers an easy water supply. We should warn, this is primitive country and on our visit on 2008, we spotted an old, somewhat grizzled bear only a few hundred yards form the campsite. Remember this is wilderness and take the usual precautions with food and cooking.
Some additional trail information for those wanting to continue south: It's about one mile south to the intersection for the Rincon La Vaca Trail. Before reaching La Vaca Creek, there's a marked, trail intersection. Take the left fork that crosses an old diversion ditch for continuing down valley. Maps do not show it, but the right fork veers into the La Vaca drainage to then join the main trail there. The actual crossing of La Vaca Creek can be a little difficult as there is no bridge and no logs to use. Either plan on a wade or take your chances on a running splash through. Beyond there, the Pine River trail is easy to follow on down to the Rincon La Osa Trail. Shortly before reaching the La Osa Creek, you'll notice some trails heading off to the right after a steeper downhill section on the main trail. These lead over to a horse-packers campsite located on a knoll. They had several large tents set up there, but we found the camp unoccupied at the time. The following coordinates are for a good campsite, just off the main trail on the west side, and located about 50 yards from the horse-packers campsite. This camp comes just after crossing a small creek that originates a short distance west of the trail. N 37° 38' 47.3" W 107° 19' 56.4". When you reach these coordinates, just look west off the trail and you should see a good area among some beetle-kill trees.
From this campsite, in 2017, we followed the Rincon La Osa trail west for three miles up valley. We found this trail to be rather boggy in numerous places and highly damaged by a horse-packing group or multiple groups making walking on the trail very difficult at times. The forest through here also has a high percentage of beetle-kill. Our main motive in supplying this additional trail information is for those who might be interested in climbing Mesa Lato - one of the top five highest 12ers. From three miles up the Rincon La Osa trail, you can turn off the trail to cross a large, wide open meadow and begin the main part of the ascent to Mesa Lato. In general, getting off the boggy, horse-trodden trail will lead to easier terrain to handle. Coordinates for the summit of Mesa Lato are: N 37° 36' 01.5" W 107° 23' 58.6". These are field validated.
We are combing Rio Grande Pyramid as the first in a sequence of three, 13er summits which would make a fairly long day from a base camp at Weminuche Pass. The other two summits are UN13,278 and UN13,261.
From our suggested base camp at Weminuche Pass, there are two trail options to reach Rio Grande Pyramid. The first option is to head south from the pass on the main trail #818 about 1.1 mile and intersect the Continental Divide Trail # 813. Before that designation was made, the section of trail to the west of this trail intersection was named the Rincon La Vaca Trail, #714. This trail heads upstream to the west, at first gaining elevation gradually, then after 1.25 miles gaining more steeply as it heads westward and northwestward in direction. After about 1.75 more miles, it intersects another trail called "The Skyline Trail," coming from the north and the base of Rio Grande Pyramid. To climb the peak, you would need to walk north on the Skyline Trail about .3 mile, then branch off to the left on use trails that lead up to Rio Grande Pyramid.
The other trail option begins at Weminuche Pass, near the suggested campsite. The "Skyline Trail" heads off to the west, marked by an old post with that name carved on it. G&JR refer to this as the "Opal Lake Trail." We're not sure where or what Opal Lake is unless it is the small pond/lake at 12,260 ft. SSE of the Rio Grande summit. Initially the trail gains elevation up along a wide ridge through open forest. At about 11,900 feet, the trail begins to break out of the trees and maintains a course below the ridge crest on the south face and begins a long contour in the direction of Rio Grande Pyramid which will come into clear view along with "The Window," a famous cleft formation in a volcanic dike south of the peak. This particular trail does show on the National Forest map, but is not numbered. It does not show on the original 1964 USGS map. On the Trails Illustrated map, it shows as a brown, dashed line, indicating lesser use and little if any maintenance.
As the trail continues its high contouring path, there will be some minor ups and downs and passage through taller willows. If the willows are wet, expect a good drenching in places. The willows provide some excellent elk habitat. In our 1994 trip, we flushed out a resting young bull who was equally surprised by our approach (probably less than 30 feet from us) and who bolted and fled by bounding and crashing through the willows a half mile before slowing just long enough to make sure we were not in pursuit, then continued on at a slower clip until out of site. This section of trail that contours well above the Rincon La Vaca does not follow the ridge crest as the Trails Illustrated map suggests, but stays well below the ridge crest as it heads west. The CalTopo map we provide gives better detail regarding this route.
The trail will turn south along the eastern flank of Rio Grande Pyramid. Follow it as it makes this turn to the south and at about the 12,200 foot level, a spur trail for Rio Grande heads off to the right and works NW to near the 12,645 ft. saddle on the NE ridge of the peak. You may actually find more than one option here. This begins the real ascent of Rio Grande Pyramid. From the vicinity of the saddle, head SW and west toward the summit using trails through tundra and rock. At times, you may lose trail because of all the rock, but there will be one a steep, sandy slope at one point where you will likely spot it. At another saddle marked on the USGS quad as 13,185 feet, the terrain turns more rocky. The clearly volcanic rocks will begin to obscure any more trail as you continue upward. It all becomes a pile of mostly broken, not-too-stable boulders. As your progress slows through this mess, the summit will seem to recede away, but stay with it and eventually you'll stand atop Colorado's 97th highest summit. Once you have seen and climbed this peak, it's prominent shape and height will become much more noticeable to you in other climbs in the San Juans. It can be seen from numerous locations. With two young teenagers in tow (ages 11 and 13) we climbed this summit in four hours from the campsite. Rio Grande Pyramid was our final Centennial summit.
The summit view offers an amazing panorama of the Grenadier and Needle mountains to the west. See our photo stitch in the gallery. After giving your weary feet a rest, hike/stumble back down to the 12,645 ft. saddle and decide if you want to continue onto the other two summits close by. If your shins have not been too badly damaged, it's worth the extra effort to not leave these two minor summits hanging.