The Colorado Independent Legislative Redistricting Commission that is looking at redrawing new boundaries for Colorado House and Senate districts has released its first proposed maps based on the latest U.S. Census data, and some Western Slope lawmakers and area residents aren’t likely to care for them.

The proposed map for House districts in Mesa and Delta counties wouldn’t change all that much, keeping Grand Junction in its own district and another for the rest of Mesa County and the western half of Delta County, including the city of Delta.

But it would greatly revise the Republican-dominated House District 57 in Garfield, turning it into a heavily Democratic district, at least based on the results of last year’s elections.

Currently, that seat is held by state Rep. Perry Will of New Castle, a Republican.

The map also would tie the western half of Larimer County — west of Fort Collins — in with Moffat and Rio Blanco counties, but still keeping it a majority GOP district.

Meanwhile, the proposed map for the Colorado Senate would divide Mesa County in two, tying the western half of the county in with all of Montrose County. The only way to get between the two counties without leaving the district is on winding, albeit scenic, Colorado Highway 141 through Gateway.

Additionally, the proposed Senate map would separate Grand Junction and Clifton from Fruita and Palisade, along with the entire eastern half of the county, including communities on Grand Mesa.

That proposed map would link the eastern half of Mesa County in with nine other Western Slope counties in somewhat of a semi-circle, going from Gunnison to Moffat to Clear Creek counties, splitting Garfield County in half in the process.

Both Senate districts would remain heavily Republican based on results from last fall’s general election, but the redrawn Senate District 5 that ties part of Garfield County with Eagle, Pitkin and Summit counties would heavily favor Democratic voters. That Senate district would include Rifle, Parachute and Glenwood Springs, but not New Castle.

Commission staff that put the map together said much of how the districts in the region were drawn was driven by a request from redistricting commissioners to keep communities in the Roaring Fork Valley together in both the House and Senate maps.

Doing so, however, resulted in splitting Mesa and Garfield counties.

“By putting Pitkin and Eagle counties together, that’s right in the center,” said Julia Jackson, a redistricting analyst for the commission who helped draw the maps. “If you put all of Garfield in, that cuts off what you can do with the rest of the map. It’s a decision of where do you get your population.”

Jackson said it’s necessary to split counties in the House map because there are nearly twice as many districts to deal with, but because Senate districts are larger, some counties also have to be divided.

She said it was unfortunate that Grand Junction was separated from Fruita and Palisade in this map, but added that things likely would change in future versions.

“I hear you about Mesa County, but we got a lot of testimony about trying not to split Delta County, which has been split a lot in the past,” she said. “Sometimes, it’s just kind of where the population lies.”

Based on election results for both House and Senate seats last fall, Democrats could continue to hold the same 41-24 majority in the House that they have now, and the same 21-14 split in the Senate.

Still, while most of those seats would favor one party or the other, the proposed maps do create some competitive seats, at least those that are within a 4% margin — six in the House and four in the Senate.

Making as many districts as competitive as possible is one of the criteria voters wanted when they approved creating independent commissions for drawing congressional and legislative districts, but that criteria takes a back seat to such things as population size, communities of interest, compactness and minority voting concerns.

The commission will spend the next week hearing from voters and interest groups about the proposed maps, and could make some major changes by late next week. Final legislative maps must be submitted to the Colorado Supreme Court for its review by Oct. 11.

To comment on the maps either at upcoming hearings or in writing, or just to see more details of them, go to https://redistricting.colorado.gov/.