One of many trip reports by Alan Silverstein.
Last update: May 6, 2008
(An article written for the Fort Collins Rockhounds monthly newsletter, the Lodestone.)
Boats float (usually), rocks don't (normally), and some of the rocks (a few) will take a polish. That was my basic premise for hunting petrified wood and other tumble-ables on the South Platte River between Brighton and Greeley.
Since rocks don't float, you can find them on gravel bars, but only above the running water, which goes up and down by the hour and day. The best rockhunting is when the boating is terrible and vice versa. But by watching the river level (available from a Colorado government website) and choosing wisely (or just accepting the inevitable bottoming-out at lower levels), I could get enough water to float my boat and still find rocks.
My odd collecting method began when I learned about "Parker wood" in southeast Denver, and started collecting it from Cherry Creek tributaries during bike rides. I discovered the fossil wood could even be found in the Platte drainage. Later this led me to driving around with a Weld County road map searching for ways to access the river north of Denver without crossing private property -- at least not above the high water line. There aren't many ways... Where's the BLM when you need them?
After walking up and downstream from below several bridges, I'd hunted (mostly successfully) all of the few stretches I could reach within comfortable walking or wading distance of where I could park. Paddling up and/or floating down the river got more appealing, and I've always liked boats... Long story short, I bought a basic kayak (Perception Swifty) on sale last spring. Since then I travelled many miles on the river between county road bridges.
First I took the kayak out alone a few times. I quickly learned that if the river was high enough to not scrape bottom much, it was too fast to paddle upstream much either. I still had fun though, wading along the edge, kicking pebbles out of my water sandals, dragging the boat behind me as far as a mile upstream and then floating back when I was done hunting -- or when the sun was going down, which usually came first.
Next I went on a so-called "slow" float trip east from Evans (near Greeley) with the Poudre Paddlers. Yup, there was some fossil wood there too. But as with most groups consisting of two or more boats -- in this case 15 of them! -- at any given moment, one crew or another was stroking away at the front, and everyone else tried to keep up. This didn't leave a lot of time for rockhunting!
So I arranged some "private trips" with my cute and patient fiance' Cathie. Three times now did our own car shuttle and explored different sections of the river, about 30 miles in all. Our typical speed was a net 1 (one) mile per hour end-to-end (GPS direct distance) including rockhunting, food, and thunderstorm stops. Even at that speed we... OK, I... had to skip about a third of the interesting-looking gravel bars. Cathie was happy to lay in her boat and read a book (sun over her shoulder) while I hunted, and then float with me when I moved on.
Some suggestions for "float rock hunting" on the South Platte:
There's a saying, "Whoever rows the boat doesn't have time to rock it," but I can attest that he who paddles the kayak can find a lot of rocks to put in it.