Launch Conditions
Use cautionLaunch with caution — limited daylight.
- Advisories
- None active
- Daylight
- Past sunset (9:13 PM)
Live from the National Weather Service, USGS, and NOAA. A guide, not a substitute for official forecasts and your own judgment.
Launch Light & Moon — June 24
local timeFirst Quarter (69% illuminated). Average fishing outlook by moon phase — focus on dawn and dusk bite windows.
Location
Quick Facts: Big Rock
| Location | Montana |
|---|---|
| Waterbody | Clayton Ditch |
| Access Type | Public - Free |
| Coordinates | 45.792938, -109.964477 |
| Hours | Check on site |
| County | Sweet Grass |
Big Rock is a public boat launch providing access to Clayton Ditch in Montana at coordinates 45.79294, -109.96448. Data published by Montana Fish, Wildlife and Parks (MT FWP).
Big Rock is a public boat launch on Clayton Ditch in Sweet Grass County, Montana. As a public launch it is open to all boaters; state- and county-run ramps like this are typically free or charge only a modest day-use fee. This page shows sunrise, sunset, and moon-phase times for the launch, updated automatically. There are 6 other mapped boat ramps within about 15 miles if conditions here aren't right.
Related: boat launch in Sweet Grass • fishing access on Clayton Ditch • Montana boat launch
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Frequently Asked Questions About Big Rock
Is Big Rock free to use?
Yes, Big Rock is a public boat launch with free access in Montana.
What water does Big Rock access?
Big Rock provides boat launch access to Clayton Ditch in Montana.
How do I get to Big Rock?
Big Rock is located at coordinates 45.792938, -109.964477 in Montana. Use the "Get Directions" buttons on this page to navigate with Google Maps or Apple Maps.
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Alternative Boat Launches Nearby
The area surrounding Big Rock includes 6 other public boat ramps within 9.9 mi, giving boaters flexibility in choosing their access point.