Safe top rope anchor off trees

Hello, I’m in lower Michigan and there is only one crag called Grand Ledge. It is top rope only with only a couple routes with bolts. Everything else is tree anchored. Some have trees close to edge other are a fair bit back. My question is what I should use to build my anchor. I will ask local but also wanted to get forum opinion. I’ve heard people saying there are some questionable anchors commonly used there.

I went once last year and used webbing tied with a water knot and girth hitched around a tree x2. 2 trees going down to a quad anchor I made. I struggled quite a bit with getting the lengths right and the anchor in the correct spot over the ledge.

Someone I had described my set up to thought it wasn’t ideal and recommended a bowline on one anchor, a clove hitch on the other going to a sling. I didn’t fully understand his verbal description.

I definitely want a safe anchor. I was hoping to follow SERENE as much as possible.

This is one standard way to do it using static rope. Two trees instead of tree and boulder works just as well as long as the trees are as big as your leg, alive, and well rooted.

https://duckduckgo.com/?q=toprope+anchor&t=iphone&iax=images&ia=images&iai=https%3A%2F%2Fcdn-files.apstatic.com%2Fclimb%2F112227093_medium_1494327659.jpg

you can also tie a bowline around both trees.  But make sure you tie the knot correctly as it is easily to tie it incorrectly. The advantage of the clove hitch is that it makes adjusting the position of the master point easier. Rethreaded figure eight knots to tie off the trees are also fine. 

You can do this with webbing, but static rope makes the knots much easier to untie.

Also, you can simplify the master point by using a BHK instead.

I highly recommend you purchase and read an anchor book, such as John Long’s _Climbing Anchors_ or the AMGA Single Pitch Manual.

One aspect of setting up top rope anchors that is frequently overlooked by new climbers is fall protection while rigging. Work out a system of securing yourself before you approach the edge. This might involve a separate piece of rope, or putting a friction hitch / gri-gri on your static rope.

One trick I learned is to tie a knot at one end of the static line (which I'd recommend for the kind of crag you're describing) then, well back from the edge, measure out enough rope to reach from the edge to your first tree/anchor point. Now pass a bight of rope pulling from the other end (so the end that will go to the cliff remains the right length) and tie a bowline around the tree using the bight of rope. Then you can use the tail end you just measured to protect yourself, using a grigri or a friction hitch attached to a locker on your belay loop, when you're equalizing and setting up the master point closer to the edge. This would require you to have a long enough static rope to reach both trees and still have some leftover for the tether end so might not work with anchor points that are really far back.

Good call above about fall protection close to the edge. If there's loose dirt/rocks or a slope above the cliff where you could slip and fall off this is probably more important than how you build your anchor.

SERENE is not needed in every situation. If a tree is 12" diameter or more you usually only need one tree. There are thousands of single trees used as anchors for climbing and rappels. You only have one rope/biner/belay device. Redundancy isn't needed everywhere. You usually want two extension lines (ropes/webbing) to the top rope biners because they could be damaged from rubbing on the edge of the rock. It's probably a good idea to use something to protect the trees (cardboard, slackline tree wraps) if this area gets a lot of top roping. And maybe something to pad the top edge of the cliff if the rope will rub on it.

Plus there is no such thing as SERENE Strong, Equalized, Redundant, Efficient, No Extension. If it's equalized (which really means load sharing, perfect equalization doesn't happen) it will have extension if one side fails (like with a quad). A quad is good if you want to top rope multiple climbs off of one anchor and want the powerpoint to slide side to side. But it's not needed for two solid trees and you can just tie a knot.