Oregon Nordic Club Portland Chapter HOME SEARCH About ONC Membership News and Events Nordic Issues Officers & Committees TRIPS Day Trips Overnight Trips Trips Guide Resources for Trip Leaders TRAILS Mt Hood Guide Mt Hood FS Trail Report St. Helens and Mt Adams FS Trail Report Topo Maps DIRECTIONS & WEATHER Directions Weather GEAR Ski Gear What to Wear Rentals and Retailers Shop Online LINKS ONC Chapters ONC Photo Gallery Nordic Skiing Other Links Send mail to webmaster with comments about this web site.   Topo Maps   Mt. Hood Map target is 45.3736ºN, 121.6925ºW  -  UTM Zone 10, N 5025067, E 602382 Exact center of display is UTM Zone 10, N 5024628, E 603504   Mt. St. Helens Map target is 45.3736ºN, 121.6925ºW  -  UTM Zone 10, N 5025067, E 602382 Exact center of display is UTM Zone 10, N 5024628, E 603504   Ochoco National Forest Map target is 44.3764ºN, 120.1167ºW  -  UTM Zone 10, N 4917507, E 729708 Exact center of display is UTM Zone 10, N 4917948, E 729488   Forest Park in Portland Map target is 45.3736ºN, 121.6925ºW  -  UTM Zone 10, N 5025067, E 602382 Exact center of display is UTM Zone 10, N 5024628, E 603504 Selecting the Right Map Size Digital Raster Graphic (DRG) maps are very large, data rich, digital images that are being presented to you online on demand. Due to the bandwidth constraints of standard phone cabling, we can produce the image many times faster than you can receive it. Our maps can be requested from the server in 3 different sizes: small, medium and large. The default setting for all downloads is a small map, unless you select another size. The size of a small map is 600 pixels by 450 pixels (approximately 110K bytes) and the size of a large map is 1400 pixels by 1050 pixels or about 700K. Tip:   A large map is therefore approximately 7 times larger (not 2.5 times larger) than a small map and will take 7 times longer to download. If you have a 28.8 or a 56K modem, you might want to stick with small maps. However, if you're going to look around a particular area, you might do better to use a LARGE map instead. After you wait for it to download, you can scroll around the big map (it will probably be much bigger than your screen) very quickly. Enlarging the Map Once you have selected your first map and you are sure that the area you want to investigate and research is centered on your initial map (click on a location to center it in the map view), you can enlarge the map by selecting either a medium or large map. Tip:   As long as you do not change map scales (e.g. go from 1:100,000 to 1:50,000), the data you have already downloaded will remain as part of your enlarged map and will not have to be downloaded again. Map Scale There are two different sets of USGS data on the TopoZone, presented to you in four different map scales. The 1:25,000 scale is the same scale as that used on USGS paper quads and the 1:50,000 scale map is the same data zoomed out to cover twice as much ground area. On the other hand, the 1:100,000 maps are generated from a different (less detailed) USGS data set and the 1:200,000 maps are the same (less detailed) data zoomed out to to cover twice as much ground area. Tip:   Generally speaking, all maps of a similar size contain the same amount of data and the scale you select has no impact on the download time. Every time you zoom in on a map or otherwise change map scales, you are retrieving a completely new map from the server and you must wait for the map to be downloaded. Cache is Like Magic! Every browser supports a cache, which allows you to temporarily store files you have previously accessed (i.e. downloaded) from the Internet. So once you have accessed any map in any given scale during a browsing session, the system does not have to go back and retrieve that map again from the server, because the data is already residing in your cache. Since your browser can check the cache first, you will save the download time you experienced the first time you downloaded that particular map. Tip:   You browser cache can be programmed to save your files for multiple sessions and you should check your system to maximize the retention of these files. But you can get carried away! If your cache is TOO big your computer may take longer to see if the file is available than it would take to just get it anyway. If your maps are loading more slowly and your hard disk is working hard while you're waiting, try clearing out your browser's cache. Navigation With the TopoZone navigation is very easy. If you "Get a Map!" you use the TopoZone search engine, which is tightly integrated with our 2 million name geographic database and is the best way to navigate to your first map or between maps that are miles apart. If a name exists on the USGS maps you can find it using our search tool. However, the spelling of the name must be exactly the same as it appears in the database. For example, you will find "Newfound Lake" if you type in the name in that order but will not find Lake Winnipesaukee if you enter Winnipesaukee Lake. And you do have to spell it correctly! Tip:   Try several different combinations of first and last names whenever you are trying to locate a place. Always spell out abbreviations. If you are not having any luck, pick the nearest town, go to the map and then scroll around at the 1:50,000 scale until you find the place you are looking for using the navigation arrows. Navigation Arrows Navigation arrows are attached to the perimeter of each map and can be used to move the map on your screen in the direction of the arrow. A portion of each map will remain on the screen and the system will retrieve additional map data from cache or the server. Tip:   Yes, in case you were wondering... you can scroll from Boston to San Francisco without ever leaving our seamless map. We have a special prize for the first person who does it and can tell us the elapsed time of the trip and how may clicks it took. No cheating - we're talking about the 1:25,000 scale maps, of course. Initial Scale and Changing Scales The 1:100,000 scale is the default setting each time you request a new map using the "Get a Map" feature. Once you have downloaded a new map, you can zoom out by clicking on the 1:200,000 scale button to get the broadest overview of the area. You can also use the scale buttons to zoom in to the 1:50:000 or 1:25,000 scale Tip:   Before navigating around, choose an appropriate scale. You might want to zoom out to 1:100,000 or 1:200,000 for moving around and then click back down to the level you want to view. Optimal Monitor Resolution The sizes of computer monitors sold today vary widely. Our user interface was optimized for a 800 x 600 pixel resolution and up, and our small, medium and large maps have been sized accordingly. If you monitor has the ability to display multiple resolutions, please choose 800 x 600 or higher for best results. If your monitor is set at a lower resolution, you'll need to scroll around the maps a bit more. Tip:   Think about your map like a photograph. We established the 3 standard photo sizes when we picked the number of pixels in each size map, and your monitor determines the size of the picture frame based on its resolution setting. Printing Capabilities Your online maps are web pages and can be printed on your home printer right from your browser. This printing capability will let you print an image of exactly what is on your screen because that's what Web browsers do. That's good news and bad news. It ensures that you can print a quick copy of the topographical map you are looking at, but the printing function is not optimized for the printer or paper size you are using. This can cause some distortion in the maps, although they will still be very useful. We recommend that you print color maps if you can because it enhances the usability of the maps. 1999–2008 Portland Chapter ONC. All Rights Reserved.