Montana Soil Drainage Rankings

Montana

How well does the soil drain across Montana? We ranked every USDA survey area by the percentage of land classified as "well drained." Areas at the top of the list have soils where water moves through at a healthy rate — favorable for building, septic, and gardening. Areas at the bottom have more waterlogged or slowly-draining soils that may require engineered solutions.

The best-drained survey area is Helena National Forest Area, Montana at 100% well-drained soils. The most drainage-challenged is Missoula County Area, Montana at 45%.

#	Survey Area	Well Drained	Poorly Drained	Dominant Class
1	Helena National Forest Area, Montana	100%	0%	Well drained
2	Bob Marshall, Scapegoat, Great Bear, and Mission Mtn. Wilderness Area, Montana	99%	0%	Well drained
3	Garfield County, Montana	99%	0%	Well drained
4	Musselshell County, Montana	99%	0%	Well drained
5	Rosebud County Area and Part of Big Horn County, Montana	99%	0%	Well drained
6	Petroleum County, Montana	99%	0%	Well drained
7	McCone County, Montana	98%	0%	Well drained
8	Yellowstone County, Montana	98%	0%	Well drained
9	Golden Valley County Area, Montana	98%	1%	Well drained
10	Phillips County Area, Montana	98%	1%	Well drained
11	Carbon County Area, Montana	98%	0%	Well drained
12	Custer County Area, Montana	97%	0%	Well drained
13	Carter County, Montana	97%	0%	Well drained
14	Liberty County, Montana	97%	1%	Well drained
15	Cascade County Area, Montana	96%	1%	Well drained
16	Fallon County, Montana	96%	0%	Well drained
17	Lewis and Clark National Forest Area, Montana	96%	2%	Well drained
18	Chouteau County Area, Montana	96%	1%	Well drained
19	Big Horn County Area, Montana	96%	0%	Well drained
20	Blaine County and Part of Phillips County Area, Montana	96%	1%	Well drained
21	Toole County, Montana	95%	1%	Well drained
22	Glacier National Park Area - Parts of Glacier and Flathead Counties, Montana	95%	1%	Well drained
23	Fergus County, Montana	95%	1%	Well drained
24	Prairie County, Montana	95%	0%	Well drained
25	Flathead National Forest Area, Montana	95%	1%	Well drained
26	Treasure County, Montana	95%	3%	Well drained
27	Richland County, Montana	95%	1%	Well drained
28	Choteau-Conrad Area; Parts of Teton and Pondera Counties, Montana	95%	4%	Well drained
29	Hill County, Montana	95%	2%	Well drained
30	Park County Area, Montana	94%	4%	Well drained
31	Sweet Grass County Area, Montana	94%	5%	Well drained
32	Valley County, Montana	93%	1%	Well drained
33	Wheatland County Area, Montana	93%	4%	Well drained
34	Lewis and Clark County Area, Montana	93%	4%	Well drained
35	Powder River Area, Montana	93%	0%	Well drained
36	Kootenai National Forest Area, Montana-Idaho	93%	0%	Well drained
37	Meagher County Area, Montana	93%	6%	Well drained
38	Stillwater County Area, Montana	93%	4%	Well drained
39	Judith Basin Area, Montana	92%	5%	Well drained
40	Roosevelt and Daniels Counties, Montana	92%	1%	Well drained
41	Lolo National Forest Area, Montana	92%	2%	Well drained
42	Broadwater County Area, Montana	92%	6%	Well drained
43	Dawson County, Montana	91%	0%	Well drained
44	Wibaux County, Montana	91%	1%	Well drained
45	Sheridan County, Montana	90%	1%	Well drained
46	Horse Prairie-South Valley Area - Part of Beaverhead County, Montana	89%	6%	Well drained
47	Glacier County Area and Part of Pondera County, Montana	89%	6%	Well drained
48	Madison County Area, Montana	88%	4%	Well drained
49	Jefferson County Area and Part of Silver Bow County, Montana	88%	5%	Well drained
50	Gallatin County Area, Montana	87%	11%	Well drained
51	Dillon Area - Part of Beaverhead County, Montana	87%	9%	Well drained
52	Granite County Area, Montana	80%	8%	Well drained
53	Big Hole Area - Part of Beaverhead County, Montana	80%	18%	Well drained
54	Powell County Area, Montana	77%	7%	Well drained
55	Gallatin National Forest Area, Montana	73%	3%	Well drained
56	Flathead County Area and Part of Lincoln County, Montana	73%	5%	Well drained
57	Red Rock Lakes Area - Part of Beaverhead County, Montana	71%	22%	Well drained
58	Lake County Area, Montana	70%	3%	Well drained
59	Bitterroot National Forest Area, Montana	70%	1%	Well drained
60	Silver Bow County Area and Parts of Beaverhead and Jefferson Counties, Montana	68%	5%	Well drained
61	Deer Lodge County Area, Montana	67%	12%	Well drained
62	Beaverhead National Forest Area, Montana	66%	2%	Well drained
63	Upper Flathead Valley Area, Montana	62%	12%	Well drained
64	Deer Lodge National Forest Area, Montana	61%	1%	Well drained
65	Bitterroot Valley Area, Montana	54%	10%	Well drained
66	Sanders and Parts of Lincoln and Flathead Counties, Montana	46%	2%	Well drained
67	Missoula County Area, Montana	45%	1%	Somewhat excessively drained