2gypsies wrote:
According the 'Mountain Directory for Truckers and RVers' (highly recommended, by the way), regarding Bear Tooth Pass "the descent from the west summit to the bottom on the Montana side (eastbound) is 22 miles of 6-8%. The road is narrow with very few places to pull over. There are numerous 15-25 mph hairpin turns.
Descending eastbound from the west summit the first 1-1/2 miles are 8% downhill followed by 1-1/2 mi. of 5-7% uphill to the east summit.
The first 4 mi. downhill from the east summit is 8% with 20 mph hairpins. Then there are 10 mi of steady 5-6% grade with very little shoulder. After this 10 mi section it opens up a little but the grade is still 5-6%. The descent is completed about 7 mi west of Red Lodge, MT.
The westbound descent is 6-7% grade with 15-25 mph hairpin turns. 18 miles further is a bridge which ices easily. The last few miles have 7-8% grades."
It doesn't sound like a fun site-seeing drive to me! :)
Let's examine some of your numbers (which you are quoting from
Mountain Directory for Truckers and RVers, I assume.)
the descent from the west summit to the bottom on the Montana side (eastbound) is 22 miles of 6-8%
It's not clear where the bottom of the highway is but I'll except your later comment that is about 7 miles from Red Lodge. (That would be 24 miles, but let's stay with your 22 miles. The greater the distance the greater the discrepancy will be.) Since there is 3 miles between the two summits,
The first 4 mi. downhill from the east summit is 8% with 20 mph hairpins. Then there are 10 mi of steady 5-6% grade with very little shoulder. After this 10 mi section it opens up a little but the grade is still 5-6%.
is talking about a 19-mile descent.
8% grade for 4 miles is .32 miles of elevation change
5.5% grade (the average of 5-6%) for 10 miles is .55 miles of elevation change.
5.5% for 5 miles is .275 miles of elevation change.
That's 6045.6 feet of descent from the east summit to 7 miles south of Red Lodge.
But Red Lodge has an elevation of 5500 feet, the east summit has ah elevation of 10,880 feet. So the elevation change between Red Lodge and the east summit is only 5380 feet. And there is a bigger discrepancy if we remember that as you leave Red Lodge, the first 7 miles are gaining elevation. (At 7 miles south of Red Lodge, the elevation is 6400 feet.) So your book has descended more that 6000 feet, where there is only 4480 feet of elevation change.
One could use the low numbers - 5% instead of the average of 5-6% and still get a total descent of 5650 feet which is still more than the total descent to Red Lodge and even more so to 7 miles south of Red Lodge.
I believe the west side numbers are equally wrong, but you don't provide enough information to do the same analysis.
All of this may sound likes I'm arguing in favor of pulling a trailer over the Beartooth Pass. But, as I stated in my first post in the thread, that is not the case.
Tom
