Hi Bob,
Sanford has a huge sandpit and some pretty good trails. To get to the trails you need to cross the river. We went on 4/29 and the river was way too deep to cross. We took the way around through the woods and it was brutal! Real deep mud! Then there's a sketchey suspended bridge to cross and the river was deep and raging just 12" below!
The payoff is the Gravity Cavities! There's a series of 6 or 7 huge cavities on the power lines that make for some real fun hillclimbing. First, you must go down a long, steep hill and then the only way out is up the other side (long and steep) or back the way you came,... BIG fun :D There's several lines up each hill: sandy, hardpack, woods - all fun and I think I tried them all.
It's not a place I'd go every weekend but it's cool once in awhile. I won't go back until the river can be crossed. If you decide to try it out be sure to let me know how you liked it!
L8r