Disclaimer: The accuracy of the CFS data provided cannot always be guaranteed. Please verify conditions before heading out.

Longmont, CO St Vrain Greenway


Safe: <100 CFS

Moderate: 100-300 CFS

High: 300-400 CFS

Dangerous: >400 CFS


Considered the crown jewel in Longmont’s trail system, the St. Vrain Greenway links numerous parks and runs five miles along St. Vrain Creek. It is part of the Front Range Trail – a regional trail with future plans to run from Wyoming to New Mexico. Existing trailheads can be found at Golden Ponds, Rogers Grove, Boulder County Fairgrounds, Izaak Walton Pond, the sundial area at South Pratt Parkway, at First Avenue near the Fire Training Center, and the western end of the Harvest Junction North commercial development.

Flow Range

40cfs to 400cfs is a good flow for tubing the Saint Vrain River in Longmont, Co. 400-700cfs is an okay flow for tubing, but the river is moving very fast at these levels. There aren’t many rapids, but there could be low hanging tree branches that could be dangerous. Lifejackets are strongly recommended at these flows, and excellent swimming ability as well.

Water Temperature

During May and June the water is typically pretty cold. When the water is over 300 cfs, it’s usually in peak snow melt time. That means, you guessed it, cold water. We rent wetsuits. The water usually starts warming up when the snowmelt is winding down.

When is it running?



40 – 400 cfs: easy to moderate. 400+ – flat but fast. Advanced tubers only.


Yes. Lifejackets and swimming ability are necessary.


The Saint Vrain Greenway is about 25 minutes from our shop in Boulder. We do not provide transportation.


Please obey any and all closures of the river. They are placed for a reason.