This route description is based on an approach backpack trip in from Twin Lakes to the south, over Coffeepot Pass and dropping into the head of Conundrum Basin with a high camp at 12,200 ft., about 1 mile SW of the hot springs. Therefore, overall mileage for the day comes in at 12 because you have to hike down the Conundrum trail over 4 miles before you begin your real ascent. Though the elevation gain from Conundrum Creek to the summit of Hunter is about 3,500 ft., you'll have to regain another 2,200 feet in elevation to return to your campsite, so the total elevation gain for the day will top 5,700 feet. Of the various summits above the Conundrum Creek area, this is the only one that would make more sense to approach from the Conundrum Trailhead along the road to Ashcroft.
From a high camp above Conundrum Hot Springs, pick up the Conundrum trail#1981 and descend the easy hiking trail north, walking another mile north past "Silver Dollar Pond," and to the bottom of a stream that drains the basin ENE of the Hunter summit. The Conundrum trail even has "bridges" for certain stream crossings. A few hundred yards south of the stream, angle uphill on open slopes toward the place where the stream exits the narrow gorge it creates. Cross the stream just below where the gully constricts, bashing your way through a few willows. You may find a game trail access through here to assist. Once across, begin making your way uphill to the west and above the creek, hiking up through aspen & evergreen forest with game trails to assist at times on the steep slopes. The forest sections are not too thick and fallen timber was not much of a deterrent. Near the end of the trees, you'll likely find the source for the stream pouring out of an embankment with a game trail leading over.
Above the trees, enter a fairly level area at the foot of the huge bowl on the east side of Hunter. Enjoy the brief respite from the steep hiking. At this point, take a more northwesterly direction and begin ascending on a mixed tundra/scree/talus slope aiming for a saddle just SW of Pt.12,839. The center of the talus cone offers some low willows and tundra for easier hiking for about 2/5ths of the gain to the saddle, but then you'll have to choose between two couloirs. The one on the right offers more tundra eventually, but as you near the saddle, you'll need to angle back over to the left. Once at the saddle, enjoy the easy and far less steep walking on tundra as you turn SW and S to the summit walking over a broad and grassy ridge section. The only difficulty remaining will be the last 200 vertical feet which will turn to large boulders that require some easy scrambling over to reach the true summit. Take in the amazing view across East Maroon Creek over to Pyramid Peak and its sub-summits to the south.
For the return trip, either retrace your ascent route or try this to save about a mile of trail hiking: From the summit, head down south along the ridge and then SE into the head of a developing gully. Follow this gully all the way into another large basin SE of the Hunter summit. This descent will be steep and mostly scree and rubble until you begin to encounter some willows and the first trees at about 11,200 feet. From there, keep working your way down through aspen & willows lower down and bash your way through willows back to the Conundrum trail. Other than some game trail activity, there was not much indication of regular, human passage. Because of the steep descending on a lot of talus and willow bashing, we do not actually recommend this route. It's probably not worth the mile you save. The ascent route described above is easier. Once on the Conundrum trail, hike back to your campsite, regaining that 2,200 feet of lost elevation if you camped in upper Conundrum Basin. There is one reward though for all this effort - a soak at the hot springs. Plan on a 9 hour day.