Tad,
Number of targets per stage, and number of stages, the sky is the limit. It all comes down to how many people you want to run through the course, and how much time you have. Also, a lot depends on the lay of the land, and how much you want people to hike between stages.
Here's an example to help get you started - Let's say this is an all-day event, starting with a safety brief at 0700, followed by the first shooter (or squad) going out at 0800 (staggered start), with the next shooter (or squad) going out at 0830, then 0900, so on and so forth, with the last going at 1030. Have two hour time limit for the course if individual shooters, or a 10-min time limit per person per stage if starting in groups. Then in the afternoon, start again with a safety brief at 1200, and the first shooter (or squad) at 1300, with the last ones going out at 1530. The guys signed up for the morning can show up early, leave early if they choose, and the guys signed up for the afternoon, can arrive later if they choose.
Another option is just send out individuals at a staggered start every 15-min, with the option to play (shoot) through, if they catch someone on the course that's slower than them (and only pass them between stages).
Stages - another example. If there's ten stages, you can average around six targets per stage, and allow 2-min per target to acquire, identify, range, engage, and hit the targets. Then add the time required to hike to the next stage, i.e. at 3-MPH, half a mile would take 10-minutes (brisk walk for the average person). An example, one stage you can have 2-pistol, and 4-rifle, then the next have 5-rifle, and the next one 1-pistol and 3-rifle, etc. This would all be dictated by the course, it's length, and the terrain.
Targets - Suggestions. I would place pistol targets between 15-yards and 50-yards, and rifle between 200-yards and 1300-yards. The reason is, at 200-yards and beyond, the targets will hold up for a long time to most calibers (under a 408 CheyTac) as long as we're talking 1/2" AR500, and the chance of damaging a strap/hanger/post is minimalized. 1300-yards is a poke for most non-Magnum calibers, but possible even with a 308 at your altitude. Most guys that know they can't hit a target over 1000-yards or so will take the penalty for not engaging or hitting the further out targets, and make it up with the time they saved. I would make all targets the same size to make it easy and help with range estimations (without a laser range finder). 10" target for everything is perfect, also a good size that can be easily and reliably ranged with both Mil and MOA reticles. Make the targets beyond 1000-yards 20" targets, and maybe throw some 5" targets out there as bonus targets, and paint them an odd color to identify as such. Target shape - if you have the space, ideally you wouldn't want any of the targets from one stage visible from another stage, but most events will have overlap of visible targets, to help with that problem, you could use 10" square targets on stage one, 10" round targets on stage two, and 10" square (hung from one corner - diamond shape) on stage three, then repeat the sequence. This method will help alleviate any confusion with both the shooter and the RO.
Range Officer (RO) - should be familiar with the course, and where all targets are. The RO tells the shooter, we have 2-pistol, and 5-rifle targets on this stage. The shooter should tell the RO, for example, I'm engaging pistol targets closest to farthest. Then I will do the same with rifle targets once I find them and range them. The RO, should know the course well enough that he would be able to follow the shooter without getting lost. Depending on how well you want to hide the targets, one suggestion I have is to number the targets (Target Post) with a big 6" number plate that's visible through most quality glass. You can have a black number on a brown placard for example that won't stand out, but would be readable when looking at the target. This would help to ensure the RO and shooter are on the same target.
Entry Fee - Allot of shooters are cheap, to put it frankly, so I would say $30 to $50 for a one day event would be average, with $100 the limit. You can add options such as $20 more for BBQ, and $75 to stay in the bunk house and have breakfast, etc. You need to be fair to yourself and paid staff also. The price of targets, T-posts, straps, flagging, stop watches, score sheets, clip boards, etc. are not free. The nice thing, there are a lot of vendors out there who will donate if approached, and with a promise that you will give them credit (free advertising). Hit up Home Depot in Casper, Murdoch's in Laramie, local Merchants (i.e. steel supplier in Casper) who will provide either free, or at a discounted price the things you need.
Awards - Having a cash prize for the first five top finishers is the average, with prize money handed out for example $200 for first place, $150 for second, etc. Other prizes - if you solicit all the manufacturers, distributors, local sporting goods/shooting/hunting retailers, you'd be surprised how quickly the prize table will fill up. Most matches the way it works, first place gets first pick of a prize off of the prize table, second place gets second pick, etc. If it's an annual event, that's when you'll usually have a prize table, if it's a monthly event, usually it will be a cash prize for the top finishers.
Schedule - If you're going the monthly event route, I suggest you make it easy for everyone. 2nd Saturday of every month, May through September. 1st Sunday of every month is the Sporting Rifle Match in Raton, so you don't want to compete with that. If just an annual event, make it May or early June while the days are still cool.
Question for you, if one wanted to camp on site, would there be showers available?