Sweet Grass County, Montana
South-central Montana · anchored by Big Timber on I-90 · Boulder River drainage · 60 mi east of Bozeman, 90 mi west of Billings
- Check current snowpack, drought, streamflow, and soil moisture before stocking, hay buying, or destocking.
- See where Sweet Grass County calves moved in 2023 — destinations, seasonal pattern, and shipping windows.
- Look up water rights, parcels, and ownership via Cadastral, DNRC WRQS, and WaterMapper.
- Reach the District 4 brand inspector and verify cattle-buyer bonds before consigning.
Snowpack · SWE
Snow Water Equivalent — water that would result if today’s snowpack melted now.
Water-Year Precip
Total precipitation since Oct 1 — the start of the NRCS water year.
Drought Monitor
Worst drought class anywhere in the county per the U.S. Drought Monitor.
D0 abnormally dry · D1 moderate · D2 severe · D3 extreme · D4 exceptional. Percentages = share of county area at or worse than each class.
Streamflow
Cubic feet per second flowing past the nearest in-county USGS gauge right now.
Soil Moisture
VWC = Volumetric Water Content — the percent of soil volume that is water. Montana Mesonet probe average.
Shallow ≈ 4″ depth · Deep ≈ 20″ depth.
Bands (shallow + deep average): ≥ 30 % moist · 22–30 % adequate · 15–22 % drying · < 15 % dry.
Precip Anomaly
Inches above (+) or below (−) the 10-year normal precipitation for each trailing window. Calendar rolling windows ending today — not the water year (see the separate Water-Year Precip tile for that).
1-mo = last 30 days · 3-mo = last 90 days · 12-mo = trailing year.
12-mo bands: > +1″ wet · −0.5″ to +1″ near normal · −2″ to −0.5″ dry · < −2″ very dry.
Reading this dashboard — what these terms mean
Median vs. mean. We use the median (NRCS standard) so a single very-wet or very-dry year doesn’t skew the baseline.
Water year. Hydrology runs Oct 1 → Sep 30. Most of a year’s snowpack accumulation is captured in the same season it melts.
Percentile (streamflow). 50 = exactly typical for this calendar date. 19 = today’s flow is lower than 81 % of all readings ever recorded on this date. 81 = lower than only 19 %.
VWC (soil moisture). Volumetric Water Content. Rough field bands: under 10 % = dry, 15–25 % = productive growing-season range, over 35 % = saturated.
Drought scale. D0–D4 from the U.S. Drought Monitor, weekly Thursday release. The percentages tell you what fraction of county area is at or worse than each band — a county can be 100 % at D2 with 0 % at D3.
Precip anomaly. Inches above or below the 10-year normal precipitation for that trailing window. Trailing calendar windows ending today, NOT the water year — the Water-Year Precip tile is the water-year measure. Anomaly is in inches; “% of median” is a ratio. Both useful; anomaly is easier to interpret when comparing a dry summer month to a wet spring month.
Forage Condition. A 0–100 county-scale index of rangeland forage conditions relative to this county’s own historical normal, blending satellite-observed vegetation response, growing-season moisture, drought stress, and usability. Higher = more favorable relative to local normal. Categories: 0–25 Poor, 26–50 Fair, 51–75 Good, 76–100 Excellent. Long-Term Forage Potential is a separate long-run rating, not part of the score. Beta — for regional screening and comparison, not a pasture-level forage inventory or stocking-rate recommendation.
How often this updates. The moisture and drought tiles (snowpack, streamflow, soil moisture, rain, water-year precip, drought class) refresh every morning. The Forage Condition score’s satellite vegetation read — and the separate Irrigated Hay/Pasture read — refresh weekly (Mondays), because the underlying satellite imagery only updates on a ~16-day cycle. So the water tiles move day to day; the vegetation reads step forward about once a week.
Sweet Grass County in context
Adjacent counties in the Yellowstone–Boulder corridor. Sweet Grass County shares the Crazies–Absaroka snowpack systems with these neighbors.
Click any neighbor for its full county dashboard.
Snowpack & Moisture Detail
SNOTEL station-by-station read for Sweet Grass County. The dashboard above gives current aggregate; this section shows where the water actually is.
Sweet Grass County snowpack is sharply split — high-elevation stations holding, lower drainages below median as of June 04, 2026. Two SNOTEL stations monitor county snowpack. Sweet Grass County watershed snowpack well below normal (county avg 72% of median); highest at Placer Basin (79%), lowest at East Boulder Mine (64%).
| Station | Elev (ft) | SWE (in) | % of Median | Relevance |
|---|---|---|---|---|
| East Boulder Mine | 6,310 | 0.0 | 64% | Lower E. Boulder drainage; nearing melt-out, no historical median |
| Placer Basin | 8,790 | 0.0 | 79% | Upper Boulder watershed — near-normal high-elevation storage |
Basin Index: Sweet Grass County watershed snowpack well below normal (county avg 72% of median); highest at Placer Basin (79%), lowest at East Boulder Mine (64%). Drought Monitor (valid 2026-06-02): D2 Severe across 43% of county; D1 Moderate across 57% of county. Total area in drought: 100% (valid 2026-06-02). Station snapshot as of June 04, 2026 — live dashboard above is current.
Two-Week Rainfall
Observed (prior 14 days) and forecast (next 14 days) · Sweet Grass County · as of 2026-06-16
| Period | Window | Rain (in) | Normal (in) | % of Normal |
|---|---|---|---|---|
| Prior 2 weeks (observed) | Jun 2 – Jun 15, 2026 | 0.18 | 1.94 | 9% |
| Next 2 weeks (forecast) | Jun 16 – Jun 29, 2026 | 0.28 | 1.25 | 22% |
Observed detail: 3 measurable-rain day(s) in the prior two weeks; largest single day 0.13 in.
Water Rights, Irrigation & Land Ownership
Sweet Grass County water rights center on the Boulder River and its East and West forks, which join north of McLeod before joining the Yellowstone at Big Timber.
The Boulder system supports some of the most productive irrigated hay meadows in south-central Montana. Water rights are allocated through the Montana DNRC priority system; rights dating to the territorial-era agricultural settlements in the 1880s carry senior positions. The Boulder River is not chronically over-allocated in the manner of the Smith or Shields; in most years senior irrigators see reliable early-summer delivery. The lower Boulder sees the most competition; upper-drainage rights on the East and West forks are generally more secure. Ditch companies serving the Boulder Valley organize delivery from late April through mid-July depending on snowmelt timing.
Production & Sales
Operation character, hay base, and how cattle reach market from Sweet Grass County.
Cattle production
Sweet Grass County supports an estimated 40,000–55,000 cattle and calves, anchored by commercial cow-calf operations in the Boulder Valley and on surrounding benchlands. Mountain summer range on USFS Gallatin National Forest allotments extends the carrying capacity substantially; most operations run a valley winter base with a mountain summer rotation. The county is predominantly commercial Angus and crossbred stock, with a modest registered seedstock presence. Elk competition for winter forage is a recurring tension in the upper Boulder drainages.
Hay & winter feed
The Boulder Valley is renowned for high-quality grass and mixed hay. Irrigated meadows along the main-stem Boulder and its forks produce reliable first and often second cuttings. Alfalfa is grown but grass-dominant mixed hay is the local standard. First cut typically runs late June to mid-July at valley elevation; second cut mid-August where water allows. Current conditions (D1, soil moisture deficits) suggest first-cut yields may be 10–15% below the five-year average. Big Timber is a regional hay trading hub; hay moves in and out of the county depending on the year.
Logistics · sale barns & trucking
Big Timber sits directly on I-90, providing among the best market access of any Montana ranching county. The primary sale outlet is Billings Livestock Commission and the Public Auction Yards in Billings — approximately 90 minutes east. Livingston (Park County) and Bozeman (Gallatin County) offer alternatives to the west, 60–90 minutes. Trucking to Billings is straightforward on I-90 with no seasonal closure risk. Private treaty with cattle buyers is the dominant channel for spring and fall calves; the I-90 corridor makes ranch-gate pickup competitive. Spring breakup on secondary roads (Boulder River Road, McLeod corridors) can delay movement in March–April.
Sweet Grass County — 2023 Cattle Movement
Source: Montana Department of Livestock, BE-10 brand inspections. Released to Honest Cattle under public-records request. BE-10 inspections are recorded at change of ownership or interstate movement, so totals reflect transactions, not the standing herd.
Top destinations outside Montana
| State | Head | Share of county total |
|---|---|---|
| Nebraska | 3,132 | 15.4% |
| Washington | 1,119 | 5.5% |
| California | 924 | 4.5% |
| South Dakota | 703 | 3.4% |
| Idaho | 554 | 2.7% |
When Sweet Grass County cattle moved in 2023
Notes: A single animal can be inspected more than once in a year if it changes hands or moves across state lines twice; destination is the buyer's state of record, which is usually but not always the final feedlot. Inspection county = where the inspection took place (often an auction yard or shipping point), not necessarily where the cattle were raised. Data covers cattle only (BE-10) and excludes horse and bison inspections.