2025-12-20T00:00:00-07:00
...THIS IS A PARTICULARLY DANGEROUS SITUATION FOR IN AND IMMEDIATELY ADJACENT TO THE FOOTHILLS, BETWEEN 5500 AND 9000 FEET, FOR BOULDER AND JEFFERSON COUNTIES ON FRIDAY... Strong west winds of 30-40 mph with gusts as high as 85 mph in the foothills of Boulder and northern Jefferson Counties will continue until early evening. Relative humidity values had dropped into the upper single digits and lower teens. Thus, the Particularly Dangerous Situation will remain in place til around 5-6 pm, with only a slow improvement thereafter as winds slowly weaken. Red Flag conditions, however, will persist through the rest of the evening as we remain in a near record warm, dry, and windy airmass along the Front Range through midnight. In fact, strong, gusty winds will persist through much of the night with only a slow improvement in humidity values. Thus, near critical Red Flag conditions will occur into early Saturday morning. While most of the Denver metro area has seen lighter winds prevail most of the day, a period of strong, gusty winds is expected to develop this evening and likely last past midnight, producing Red Flag conditions there. * AFFECTED AREA...Fire Weather Zones 238, 240, 241, 242 and 243. * TIMING...Until midnight MST tonight. * WINDS...West 15 to 25 mph with gusts up to 50 mph. * RELATIVE HUMIDITY...As low as 9 percent. * IMPACTS...Conditions will be favorable for rapid fire spread. Avoid outdoor burning and any activity that may produce a spark and start a wildfire.
Summary
Total streamflow across the
Marias River
was last observed at
1,900
cfs, and is expected to yield approximately
3,769
acre-ft of water today; about 149%
of normal.
River levels are high.
Average streamflow for this time of year is
1,276 cfs,
with recent peaks last observed
on
2011-06-10 when daily discharge volume was observed at
18,600 cfs.
Maximum discharge along the river is currently at the
Marias River Near Shelby Mt
reporting a streamflow rate of 1,900 cfs.
This is also the highest stage along the Marias River, with a gauge stage of
4.93 ft at this location.
This river is monitored from 3 different streamgauging stations along the Marias River, the highest being situated at an altitude of 3,099 ft, the
Marias River Near Shelby Mt.
River Details
| Last Updated | 2025-12-19 |
| Discharge Volume | 3,769 ACRE-FT |
| Streamflow |
1,900.0 cfs
-210.0 cfs (-9.95%) |
| Percent of Normal | 148.94% |
| Maximum |
18,600.0 cfs
2011-06-10 |
| Seasonal Avg | 1,276 cfs |
River Streamflow Levels
| Streamgauge | Streamflow | Gauge Stage | 24hr Change (%) | % Normal | Minimum (cfs) | Maximum (cfs) | Air Temp | Elevation |
|---|---|---|---|---|---|---|---|---|
|
Marias River Near Shelby Mt
USGS 06099500 |
1900 cfs | 4.93 ft | -9.95 | |||||
|
Marias River Near Chester Mt
USGS 06101500 |
253 cfs | 2.95 ft | 1.61 | |||||
|
Marias River Near Loma Mt
USGS 06102050 |
335 cfs | 0.86 ft | -3.18 |
Seasonal Discharge Comparison
Maximum Streamflow Discharge
Streamflow Elevation Profile
The Marias River is a tributary of the Missouri River, approximately 210 mi (338 km) long, in the U.S. state of Montana. It is formed in Glacier County, in northwestern Montana, by the confluence of the Cut Bank Creek and the Two Medicine River. It flows east, through Lake Elwell, formed by the Tiber Dam, then southeast, receiving the Teton River at Loma, 2 mi. (3.2 km) above its confluence with the Missouri.
The river was explored in 1805 by the Lewis and Clark Expedition. Some of the men on the expedition mistook it for the main branch of the Missouri until their subsequent discovery of the Great Falls of the Missouri near Great Falls, Montana. The river was named by Meriwether Lewis after his cousin, Maria Wood. Lewis led a small detachment of men to further explore the Marias River on the Expedition's return trip in 1806 to determine if the river ventured north above the Canada border, and he killed a young Blackfeet warrior trying to steal horses and a gun from the small detachment.
The river was the scene of the 1870 Marias Massacre.The Marias is a Class I river from Tiber Dam to its confluence with the Missouri River for public access for recreational purposes.The Montana Watershed Coordination Council is an advocate for the river.The Marias River Bridge was listed on the National Register of Historic Places in 2012.