Need to lighten the load for some waterfall hiking.

First of all, consolidate your two systems into one. You can always get another body from the same brand that can take those same lenses.

As I'm getting older lightening my load makes sense so I feel your pain. First I would settle on 1 new camera system or pick 1 from your 2 and leave the other in the hotel in case 1 breaks but don't carry both. I have let go of my trusted, old and too heavy manfrotto 3021pro. I got a feisol CT 3342 (- http://www.feisol.net/tripods-tournament-class-c-1_14.html). It is 2.4 lbs w/o my ball head. Best move I made, you just smile when you lift it up. So I would find a sturdy but lighter tripod. Depending on the hike I try to just take my belt system ( think tank - http://www.thinktankphoto.com/categories/skin-component-systems.aspx), 1 body, 2 lenses, batteries,filter ect, and tripod case that came with feisol that I sling over my back. Or I take a backpack and hook my tripod on. Either way I have my hands free. I decide before I hike what lenses I think I will need and live with my compromise and don't beat myself up when I wish I had another lens. By the way I have no connection with feisol or thinktank just like the products.
good luck Paul

I agree lighten up, simplify, consolodate. I use one of three very simple efficient kits depending on what I want in the end. I still shoot a lot of black and white so these are film kits. Hasselblad with WLF and one lens mounted on a Manfrotto field tripod along with a small bag of film, cable release and filters. Or a Nikon N90 with old Tamron 28-80 SP, 50 1.8 AIs and old Tokina 70-210 mini zoom, along with a few filters and Hoya 4+ close up lens to put the Tokina at 1:1. I will usually take the tripod along here too. Last is my most lightweight, two Minolta Maxxum 70 bodies, one with 28-80 kit lens and the other with 75-300. If I go digi I will substitute D200 for N90. These are all kits I can walk with and not feel depressed by the time I get to my shooting area. I will attach a pic if it will upload.

Yeah, I'm 64, and I can't see scrambling up and down stream banks with a heavy tripod weighting me down. It looks that the CF is going to have to be the first step in going light. I tried the backpack tonight with just two bodies and a wideangle for each and it feels manageable in terms of weight. However, I'm taking your advice, when in the field will go with one body and a beltpack. Thanks for your comments and ideas.
Gene

We're about the same age Gene, and I have gone through much the same exercise in determining what I really need to carry. Part of my solution has been investing in tripods - I choose from two when hiking:
1) Gitzo GT-0531 with RRS BH-25 w/quick release - this weighs exactly 2 pounds and is perfect for long hikes, gets me sufficient stability for most landscape shots and is fine with any short to medium lens. With longer focal lengths it merely helps and it isn't particularly tall. It is so light that every time I pick it up I smile.
2) Gitzo GT-1541 with Markins Q3 Emile Ball Head with quick release - this weighs about 3 1/3 pounds, but is much more stable and taller. I choose this for shorter hikers or when I know I'll need the additional height and stability. I've found this combination almost as good as a larger tripod with Arca Swiss head, at about half the weight.
I couldn't find alternatives that were lighter and/or capable of supporting weight with more stability. I could finder cheaper alternatives, but I feel my return on investment, particularly given the warranties and the quality is excellent.

I'd also pick up another body of the same brand and carry only one line of lenses. I love my D90 (btw) and would buy it again in a heartbeat.

First, there is no way to seriously lighten your load with 2 different camera bodies that require two different sets of lenses. Chose one or the other and get a second body of the same type. Second go with the Manfrotto. There is nothing more useless than an unstable tripod, no matter how light it is. Locally many of the waterfalls are in forested areas requiring long exposure times. Third weigh your pack. You will be surprise at how much your backpack can weigh and how variation in weight you can find with different types of brands of backpack.

Danny

Gene, it is a good idea to have a backup body, but it should be of the same brand as your main body so that they can share lenses and accessories. The second body can stay in the car or in the motel; you don't have to carry it all the time.

A good but small carbon fiber tripod should be the way to go.

I agree, for outdoor adventure or landscape, you need your backups to be the same lens mount or be able to take the other brand with an adapter. If you are shooting from the trunk of a car, then it probably doesn't matter but on the trail it does.

So first thing I would do is choose Olympus or Nikon. Like Shun said, you should have some sort of backup with you on a trip but you don't need to carry 2 bodies with you at all times.

Second, leave a body at home (car, camp, hotel) if the weight is an issue. true it sucks to hike in only to find out your camera is dead, but if you've had it for a while, it probably won't just up and die.

I also agree with Danny, if photography is your sole goal, that is you aren't trying to get some really good shots while hiking, but rather you are setting out with the only goal of getting the best images you can, don't skimp on the tripod. If you are backpacking in, than sure the tripod might be something you compromise. I've never believed that you cannot get great results from mostly any decent tripod with a little compromising. But why compromise on a day hike?

So 1 system, a light but sturdy tripod, and a decent backpack. For short photo specific hikes in warm weather, I like my LowePro Primus AW. it will hold a body and lens + 2-3 additional lenses. It is also an excellent backpack, not just a camera bag with backpack straps on it. A really nice suspension that carries the load well. You can put a hydration sleeve (like a camelback) in the expansion pocket that is outside the main bag. I have an insulated hydration sleeve that slides in there and keeps 2 liters nice and cool. The tripod straps nicely on the outside of all of that with a dedicated system. Up top there is room for a first aid kit, an extra layer, some food, and your photo accessories.

All of that, with the tripod, should come in under 25lbs, maybe like 20-22 with water and a lighter carbon tripod.

One other thing to consider. When you go on these hikes you are leaving yourself open for break ins. I have seen many cars broken into over the years at trail heads, I wouldn't want to leave a lot of equipment in the car one way or the other.
As others have noted a body backup should be compatible. I shoot Pentax medium format and thus I can use Pentax 35mm bodies as backup for the MF. More generally I'd just bring a second 35mm body.
For waterfalls I also always bring two types of filters, ND and Polarizers. I realize they don't add much weight, but you probably should remember to bring them too.