Sawback Trail :: Forty Mile Rainbow

This segment describes "Fitch Variation" of Sawback Trail between Mystic Junction (FM19) and Flint's Park (CR31).  On my visit, according to overall strategy, I made a "basecamp" at FM19 then dayhiked with light pack;  this gave me plenty of time to explore fantastic - and not quite expected - Forty Mile Summit and beyond Alpine area.   There are two major highlights situated at opposite sides of main corridor - Sawback and Rainbow Lakes.  Most Sawback backpackers simply hike through missing both, and that is the shame due to extraordinary beauty and overall remote feel.   After hiking to Forty Mile summit I made a loop:  First visited Sawback Lake, then looped back via lower Rainbow Lake Connector and back to Forty Mile as shown on following two maps:


FM10 to Sawback Lake MapFM10 to Sawback Lake Map

FM19 - Forty Mile Summit - Sawback Lake  (click for full size)

Distance: 11km, Elev. Gain: + 450m,  Elev. Loss: - 270m

Rainbow Lake Loop MapRainbow Lake Loop Map

Sawback Lake Junction - Rainbow Lake Loop (click for full size)

Distance: 10km,  Elev. Gain: +360m, Elev. Loss: -200m

Section between FM19 and Forty Mile Summit is ~6.5km and mostly forested.  There are two trails: Horse that stays lower mostly following the creek, and Hiker Bypass on east side.   Horse trail should be avoided by all means as it is deeply rutted and has many non-bridged creek crossings.  However Hiker Bypass was not smooth sailing either, with many fallen trees and collapsed bridges;  apparently Parks Canada is not maintaining this trail anymore.  There were also large amount of huge frogs on trail the whole day and it took real effort sometime not to step on them, as they moved quite slowly.  Hiker and Horse trail rejoin ~1km before Forty Mile summit; extraordinary alpine meadow ~2km long.   Upper Rainbow Lake connector splits on the east side roughly halfway along the meadow. It is not signed and easy to miss - see last photo in gallery.  Trail then descends steeply ~150m vertical and crosses Sawback creek on good  bridge to junction:  Sawback Lake left in ~2km, Flint Park right ~4km.   CR31 campground is halfway to the lake and would be great base to further explore the valley. 


After visiting Sawback Lake I dropped ~30min down Flint trail to lower Rainbow connector.  Fallen park post missing sign was yet another example of Parks not maintaining this area anymore.  Rainbow creek crossing is directly below and there is no bridge.  Hike to the lake will take good hour, but it is very beautiful mostly on semi-open escarpment with great views to the west - see gallery.  Eventually it merges with upper connector by big larch few minutes before the lake.  Rainbow lake is extraordinary, to say the least.  There are larches all around and it would make great late September destination too - only if it wasn't so far.   In 2015 Parks Canada flew batch of Westslope Cutthroat trout from Sawback to Rainbow Lake, attempting to preserve this fish species native to Banff National Park.  Ridge above the lake on south side begs to be hiked;  it would provide great views of Mt. Sira, and looking at maps one could probably descend on the other side to next valley south which contains yet another wilderness lake, likely never visited - so much room for exploration.  Upper Rainbow connector to Forty Mile summit is shorter and after couple of switchbacks gradually descends to main trail ~45min from the lake.


Backpackers making through hike will have some logistic issues visiting both Sawback and Rainbow Lakes.  Most practical approach is probably to stash heavy overnight pack at Forty Mile summit, then hike upper Rainbow Connector out-and-back.  Same strategy can then be used at Sawback/Flint junction for visit to Sawback Lake. 

Hikers Bypass One of several decaying bridges on "Hikers Bypass" between FM19 and Forty Mile Summit
Horse Junction Park Table as Hikers Bypass merges with Horse trail just below Forty Mile Summit
Forty Mile Summit Forty Mile Summit - incredible 2km stretch of classic Rockies high Alpine Meadow
Forty Mile Summit Terrific View of Mt. Sira (upper center right) from Forty Mile Summit
Forty Mile Meadow North Part of Forty Mile Meadow with distant views to Cascade North Fork above Flint's Park.  Upper Rainbow Trail splits to the right just before this spot
Sawback Creek Bridge Hikers Bridge over Sawback Creek after steep, but short descent from Forty Mile Summit


Sawback Creek Sawback Creek looking towards cirque that holds Sawback Lake, ~2km away

Sawback Lake Junbction Park Table at Sawback Lake Junction; FM29 campground is ~15 min from here.  Fitch Variation continues north towards Flint Park. 
Sawback Lake Sawback Lake Outlet after brief ascent of semi-forested headwall on good trail
Sawback Lake Table Weathered Park Table at Sawback Lake Outlet;  I've seen similar on several eastern BNP backcountry lakes
Sawback Lake Gorgeous Sawback Lake Panorama; one of most beautiful BNP backcountry lakes I've seen.  Faint trail exists on right (north) side. Optimal light for photography is in the morning, ideal if you are camping at FM29.   
Sawback Lake Another shot of Sawback Lake looking back towards outlet from little nook on north side
Sawback Meadows Hiking back from Sawback Lake towards Flint Park/Forty Mile junction
Lower Rainbow Junction Lower Rainbow Lake Connector by decayed Park table without sign anymore.  This is looking back towards Forty Mile;  Rainbow trail is left
Rainbow Crossing Unavoidable creek crossing at Lower Rainbow connector;  this is looking back towards Flint trail
Rainbow Escarpment Great hiking on semi-open ridge towards Rainbow Lake cirque
Block and Noetic Noetic Peak (center) and Block Mountain (right) looking north from lower Rainbow Lake trail
Rainbow Escarpment Looking west towards Sawback Lake environs, already quite far away, from lower Rainbow Lake connector.  Forty Mile summit upper center left
The Big Larch Lower and Upper Rainbow Lake trails merging by that tall larch center left.  Lake is just a few minutes away
Rainbow Table Similar Park table as earlier at Sawback Lake
Rainbow Lake Panorama of Secluded and rarely visited Rainbow Lake from west side.  "Larch Ridge" upper right
Rainbow Lake Unnamed peak reflected in calm water of Rainbow Lake by the outlet
Rainbow Lake Another shot of very picturesque Rainbow Lake after crossing the Outlet.  Larch hammock where trail ends is far center right.  "Larch Ridge" directly across
Upper Rainbow Junction Upper Rainbow Lake trail junction to the right after returning to Forty Mile Summit



Overall Difficulty D3 Sections with deadfall on Horse bypass to 40Mile summit.  Some rocky/rooty parts.  Mid-calf creek ford on lower Sawback connector
Snow Factor S2 No avalanche danger, but remoteness of the area does not lend itself for winter trip 
Scenery Forty Mile Summit Alpine Meadows.  Beautiful Sawback and Rainbow Lakes
Trail/Marking Very Good Official park Trail over Forty Mile Summit to Flint's Park with marked junctions.  Hikers Bypass from FM19 likely not maintained.  Rainbow Lake connectors not marked
Suggested Time 7-8hrs Loop return from FM19 or FM19-CR31 through hike with Sawback Lake/Rainbow Lake side trips
Gear Full Hiking Boots, Poles and Overnight gear
Water Forty Mile creek, Sawback and Rainbow Lake outlets.  No need to carry more than 1L at any time
Dog Friendly No Although I've seen backpackers with dogs on Forty Mile, this is strongly discouraged because of overnight logistics

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