South Fork Flathead flow guide
There’s no way to verify, but all evidence points towards the number of packrafters on the South Fork being an all-time record this year; a number certain to only grow. I’ve been getting lots of questions concerning what flow levels are best and what speeds to expect, and what follows are my best estimates.
The wilderness portion of the South Fork can be divided into four or five sections, each with a different character:
1) confluence to Big Prairie pack bridge
2) Big Prairie to White River
3) White River to Salmon Forks
4) Salmon Forks to Black Bear Creek
5) Black Bear Creek to Mid Creek takeout
They are described below in turn. All cfs references are to the Twin Creek gauge.
1) This section is open, meandering, with big views, good camping, and (after the high runoff of 2011) extensive log jams. At flows much below 1200 cfs this section gets pretty draggy, and packraft speeds will likely average below 2 mph. At around 8000 cfs this section is a laugh, and speeds approach 5 mph.
2) Below Big Prairie things get a bit more constricted, and Burnt Park has what are two of the cruxier rapids at lower flows (between river miles 8 and 10.5). At 5000cfs or above these get washed out and are noticeable only as slightly bigger wave trains. Low water speeds (below 1500cfs) are 2-2.5 mph, while around 8000cfs speeds likely approach 8mph in the more constricted sections. Below river mile 11 things mellow out and the river from here to Big Salmon is very similar.
3) From White River to Salmon Forks the river splits the difference between the first and fourth sections. At lower flows, there are plenty of braids and gravel bars set within low dirt hills, and no obstacles of consequence. Speeds below 1500cfs approach 3 mph. Below 800cfs, they’re closer to 2, with lots of rocks to avoid.
4) Below Salmon Forks (the entrance of Big Salmon Creek) the river becomes more concentrated, with steep pine-covered walls. This is probably the point below which floating is decent at just about any level. Speeds between 1000 and 1500cfs are around 3mph. At lower levels floating is mellow. Above 5000 or so cfs things get pushy, with the many riffles morphing into larger and larger rapids.
5) In the short stretch between Black Bear Creek and the Mid Creek takeout are several tricky bedrock rapids and micro-gorges, which are worth paying heed at any level. Speeds are relatively fast, and the fishing is excellent. Watch out for the final takeout warning sign, which is well above river level and midway through the rapid right after the takeout gravel bar. I’ve not run Meadow Creek gorge itself, and cannot comment.