Community Forums

RV4US2022 · 05-15-2022, 09:14 AM

Can someone tell me the Hwy out of Montana into Idaho that is extremely steep? I took this road a few years back in a 1977 GMC and it was challenging. I am now in a DP but don’t want to take it again.

Can’t remember the Hwy #

Skip426 · 05-15-2022, 09:57 AM

The I-90 has some grades , but so does every route over the Great Divide .

I drive the 90 on an annual basis .

Slow to 45 mph at the summits of the passes and control you downhill speed with engine brake; coast on the engine brake to 50/ 55 and hard braking with the service brakes back down to 45 ,then long periods of coasting to cool the brakes .

I will say that if any of the routes MT to ID have stuck in your memory , then stay off the I-84 in OR , the drop into Pendleton from La Grande will give you fits . summit there , you start out at 30 mph and 6>7 miles of downhill .

**Camp CA** · 05-15-2022, 09:59 AM

These are the steep grades > 7% listed in Mountain Directory:

Idaho Highway 71 between Cambridge and Brownlee Dam has 4.5 mile of 9%
Montana Bear Tooth Pass on Highway 212 of Red Lodge 6-8%
Montana on highway 12 west of St Helena 8%

https://www.mountaindirectory.com/cb...l?hop=flex7878

TexasJack · 05-15-2022, 10:21 AM

I don't recall driving steep grades in that area.
One I know of, and avoided, was from Jackson Hole going East. Long and steep with a bad reputation.

vsheetz · 05-15-2022, 10:41 AM

Maybe you are thinking of highway 22 from Jacksin Hole WY to Idaho. Looping south through Swan Valley is a scenic bypass.

twogypsies · 05-16-2022, 01:36 AM

From your Profile you have a 2021 Newmar NewAire DP so any hill shouldn't be a problem.

I think we've done just about every road in that area - a favorite of ours.

I suggest you get the 'Mountain Directory for Truckers and RVers'. We used it all the time even if we've driven the road previously. It was always good to refresh our memory as to what's ahead.

Have fun!!

1JetDoc · 05-22-2022, 10:38 PM

Quote:

Originally Posted by RV4US2022

Can someone tell me the Hwy out of Montana into Idaho that is extremely steep? I took this road a few years back in a 1977 GMC and it was challenging. I am now in a DP but don’t want to take it again.

Can’t remember the Hwy #

Montana into Idaho covers a lot of territory! Maybe if you narrowed your route down a bit it would be easier for someone to give advice. What cities did you want to pass through?

twogypsies · 05-23-2022, 01:27 PM

You may be thinking of Hwy 95 into Lewiston, ID. It's a long, steady downhill with 3 runaway truck ramps. That said, it's a very popular highway for RVers.

Another one is Lolo Pass on Hwy 12... a lot easier.

Then there's Hwy 55 between McCall and Meadows, ID;

ID 71 between Cambridge and Brownlee Dam

ID95 north of Weiser

I-90 at the MT/ID state line

Lots of fun drives in the awesome state of Idaho!!