Mapping the past

GIS technology creates accurate pictures of old townships

The Flathead River meanders and buildings tumble down but old towns can't elude Denny Rea, Mindy Cochran and other experts using Geographic Information Systems in the Flathead County Plat Room.

"When any of the old townsites come to me, I can georeference them on the maps," he said.

Rea, a GIS analyst, confesses to a love of history that made him the perfect man to assist the History Is Posh group pin down Demersville and a host of other towns that vanished over the last 100 years.

He said the request from HIP couldn't have come at a better time.

"This is the first time we've been able to breathe in a few years," he said. "This gives us a chance to get some of these records organized."

It also came at a time in technology when Rea has GIS (Geographic Information System), a computer system that integrates mapping software with land surveys, aerial photography, GPS road positions, mathematics and more.

Mindy Cochran, GIS program manager, said the development process required feeding in survey positions for every section of each township across the county to create parcel maps. It was complicated by changes in jurisdictional boundaries through the years.

"We had to go through 100 years of territorial transfers," Cochran said. "It was a very time-consuming process."

She said that Rea did a great job of using GIS technology to layer the GPS road center lines, parcel and aerial maps to accurately place the historical townsite of Demersville on today's landscape.

"What was amazing was how well the river banks lined up," Rea said. "We have some of Demersville in the (Flathead) river. I think that's due to the 1913 flood and then the '64 flood."

He used the same process to produce maps of Ashley, once in the vicinity of Meridian and Foy's Lake Road, and Jessup, next to the Creston fish hatchery.

Rea picked reference points on the original maps or townsites to link up with their equivalents on an up-to-date digital map. With control points established, he then applied mathematical algorithms to "warp" the original map to fit the accurate base maps.

He said that Demersville was an easy fit but Ashley and Jessup were a greater challenge. He said the area of Ashley has a history of survey problems so he took advantage of a legal description of a property as a reference point to help locate the town.

"Ashley's main street went right up Meridian," he said. "It became a ghost town. The property was purchased by Conrad and made into the Kalispell townsite."

Rea used a hand-drawn map to help pinpoint Jessup for the history group. A very early town (pre-1880), Jessup had a brewery, a flour mill and a sawmill that produced most of the lumber used in building Demersville.

"There's a very nice piece on Jessup on the Internet," Rea said.

The article called "A History of Upper Mill Creek and Jessup Mill Pond," by Debbie Sanders and Keith Hammer, included the hand-drawn map, locating the mill pond near today's Creston Fish Hatchery.

Along with old maps, Rea can sometimes use old photos to provide reference points to place historic sites.

"That's one good thing about living in a valley -mountains," he said.

HIP's requests were just a few of many received in county offices, according to Jan Hardesty, records manager. She said people often call when researching their ancestors who lived in vanished towns such as Ashley and Demersville, asking "Where is that?"

Hardesty hopes the county can furnish historical maps on the Internet in the future for genealogists searching for people and places of the past.

"We'd like to have a link on our site," she said.

Reporter Candace Chase may be reached at 758-4436 or by e-mail at cchase@dailyinterlake.com.