Most Flood-Prone Counties in Montana

Based on NOAA Storm Events Database records from 1996 to 2025, these are the Montana counties with the most recorded flood events. Valley County tops the list with 123 events. The data includes river floods, flash floods, coastal flooding, and hurricane-related flooding.

Rank	County	Total Events	River Floods	Flash Floods
1	Valley County	123	85	38
2	Phillips County	55	42	13
3	Roosevelt County	52	27	25
4	Lewis and Clark County	39	18	21
5	Flathead County	39	34	5
6	Richland County	37	21	16
7	Yellowstone County	37	13	24
8	Garfield County	36	16	20
9	Missoula County	36	33	3
10	Musselshell County	35	9	26
11	Dawson County	32	22	10
12	Powder River County	32	9	23
13	Custer County	31	11	20
14	Ravalli County	30	21	9
15	Cascade County	30	15	15
16	Rosebud County	28	12	16
17	McCone County	25	9	16
18	Sanders County	25	24	1
19	Big Horn County	24	11	13
20	Petroleum County	24	17	7
21	Prairie County	24	11	13
22	Blaine County	22	17	5
23	Gallatin County	22	20	2
24	Carbon County	21	9	12
25	Granite County	21	18	3
26	Silver Bow County	20	14	6
27	Stillwater County	20	8	12
28	Daniels County	19	11	8
29	Powell County	19	17	2
30	Lincoln County	18	18	0
31	Wibaux County	18	10	8
32	Deer Lodge County	18	16	2
33	Lake County	17	16	0
34	Fallon County	16	2	14
35	Fergus County	16	11	5
36	Sheridan County	15	11	4
37	Golden Valley County	14	6	8
38	Carter County	12	6	6
39	Sweet Grass County	11	6	5
40	Treasure County	11	8	3
41	Chouteau County	9	7	2
42	Teton County	9	6	3
43	Wheatland County	9	5	4
44	Madison County	9	9	0
45	Hill County	8	6	2
46	Beaverhead County	8	4	4
47	Glacier County	8	6	2
48	Pondera County	8	6	2
49	Jefferson County	7	4	3
50	Mineral County	7	6	1
51	Toole County	7	2	5
52	Park County	7	6	1
53	Meagher County	6	4	2
54	Judith Basin County	6	5	1
55	Broadwater County	5	3	2
56	Liberty County	2	2	0

Source: NOAA Storm Events Database (1996–2025).

Check Your Property's Flood Zone

Free instant lookup using official FEMA data