RBM goes volunteering with Montana FWP

I love to volunteer for events, especially if it involves digging around in the river on a beautiful morning for the benefit of trout.  Today, I was part of a small crew assisting Montana Fish, Wildlife & Parks with some maintenance on an important local fish ladder.

Marshall Creek fish ladder

Quick Background Bullet-points:  

• Marshall Creek is an important spawning tributary for cutthroat and rainbow trout that reside in the Clark Fork River.
• The creek comes out of the mountains and goes underneath the highway through a large concrete culvert to reach its mouth at the Clark Fork River.  The outlet of the culvert used to be perched way up above the Clark Fork.  Ladd Knotek of MTFWP said that trout attempting to spawn could not make it up into the culvert and into Marshall Creek. Mr. Knotek also mentioned that for a time, the stream was considered a pure strain cutthroat stream due to this disconnection.  In 1997 the Clark Fork experienced a major spring runoff and, due to the high gage height of the river, the distance to the culvert was breached by some rainbow trout.  Rainbow genetics showed up in the local population of cutts.  This made the stream a candidate for the ladder and a re-connection to the rest of the system.   
• In 2003 the fish ladder was built "basically by hand" due to difficulties posed by the location.
• Biological monitoring of Marshall Creek since the installation of the ladder has shown that it is very effective and that it is heavily used. 
• The ladder was originally armored with a bunch of angular rocks on that leading edge.  Most of the reinforcement has washed away over the years along with the rocks which provide the structure for the bottom pool.  These rocks also hold an important metal baffle in place.    

When the rainbow and cutts are spawning, the level of the Clark Fork usually comes up to even (sometimes more than) with the pool at the bottom of both cascades.  The fish enter the ladder by jumping out of that pool and into the opening of the concrete structure in the right of this picture.  They then ascend a series of pools and turn the corner...

Once they're out of the ladder, they are at the height of the old culvert.

Once inside the culvert, the trout benefit from these baffles which were installed in the culvert to slow the flow of water and provide rest areas.

Will Schreck from MT FWP with 2 guys from Westslope TU hauling rock

Salmonfly (Pteronarcys californica) nymph 

re-built bottom pool

Our hard work put the ladder in good shape to provide our local trout access to their spawning grounds.  I hope they all get up there and get it on nasty!!

Volunteer season is here!  Stay tuned for more opportunities.  I will post them here.  There is a such thing as trout karma!