Great Cleft is somewhat of an overly grandiose name for the narrow chimney that gives this route its name. It is, never the less, an extremely fine and unique way up Pollock Mountain that provides one of those Glacier Park surprise easy ways where appearances would otherwise indicate extremely difficult climbing. This is certainly the most interesting of the three established routes on the peak.
The route is approached from the saddle between Pollock and Piegan Mountains.
The saddle is most commonly approached via Lunch Creek (the first creek east of Logan Pass). There is a parking area where the highway crosses the creek. A very good trail leads from the road to the base of a cliff band with a waterfall. A less distinct trail leads up the cliff band east of the waterfall into the basin above. Once in the upper basin, trend right and watch for good goat / sheep trails in the talus to the east that lead to a shallow eastward trending couloir through the steepest lower cliff bands. This couloir is the easiest way to the easier upper slopes below the saddle, but it has a lot of very loose rock. We exited the couloir as soon as it was practical to get on firmer ground. In early season, expect to find steep snow in the couloir and be prepared with ice axe and crampons. Via this route, it is about one mile and 3,000 vertical feet from the road to the summit.
Another approach to the saddle is from Piegan Pass to the northeast. This option involves 4.5 miles of trail, about one mile of cross country travel, and about 3,500 vertical feet of gain. It is more commonly used as a descent route from the saddle.
From the saddle between Pollock and Piegan Mountains, ascend to the base of the cliff band at the corner of the southeast ridge of Pollock directly above the saddle.
From this point, the Edwards Guide makes finding the "Great Cleft" sound very easy. As stated, simply follow the game trail below the cliffs to the west until directly below a huge "finger" of rock, then simply: "Go about 110 normal steps from the base of that finger, then look upward toward the northeast."
However, there is more than one "finger" of rock. And the first and most obvious is not the correct one. Proceed past the first and very obvious finger to the next small buttress. This small buttress is the correct finger, but it does not appear to be a separated tower until it is viewed from well to its west. See the two photos left and right.
Make an east (climber's right) trending ascent into the shallow basin west of the tower. You will soon see the narrow chimney between the tower and the main peak. From this vantage point, the chimney appears to just go straight up to a notch with no indication at all that there is anything on the other side but lots of air. But, have faith.
Edwards describes approaching the chimney from the north and lowering yourself into it. We were able to climb directly to the base of the chimney a just start climbing - no lowering involved.
The chimney is very narrow and vertical for about the first 15 feet. If it were not so secure, the climbing might be rated more than Class 3, but even Edwards states specifically that there are "no ropes needed". The angle soon lessens and one merely scrambles up and through the remainder of the chimney and finds themself on a broad and easy slope leading to the summit.
There is extreme rock fall danger in this narrow chimney. The safest option is for members of the party to climb it one at a time.
Essential GearNormal gear for a day of scrambling in the Park.
Some parties may wish to have a rope for the initial 15 feet of the chimney.
GuidebooksA CLIMBER'S GUIDE TO GLACIER NATIONAL PARK; J. Gordon Edwards
A detailed route description is included in CLIMB GLACIER NATIONAL PARK Volume 1