<Page> Exhibit 99.9 [LOGO OF NORTHWESTERN CORPORATION] - -------------------------------------------------------------------------------- FINANCE PRESENTATION MARCH 2002 <Page> DISCLAIMER - -------------------------------------------------------------------------------- CERTAIN STATEMENTS MADE IN THIS PRESENTATION, INCLUDING THOSE RELATING TO EXPECTATIONS OF FUTURE FINANCIAL PERFORMANCE, CONTINUED GROWTH, AND CHANGES IN ECONOMIC CONDITIONS OR CAPITAL MARKETS ARE FORWARD-LOOKING STATEMENTS THAT INVOLVE INHERENT RISKS AND UNCERTAINTIES. A NUMBER OF IMPORTANT FACTORS WHICH ARE DIFFICULT TO PREDICT AND MANY OF WHICH ARE BEYOND OUR CONTROL, COULD CAUSE ACTUAL RESULTS TO DIFFER MATERIALLY FROM THOSE IMPLIED BY THE FORWARD-LOOKING STATEMENTS WITHIN THE MEANING OF THE "SAFE HARBOR" PROVISIONS OF THE SECURITIES ACT OF 1933 AND THE SECURITIES AND EXCHANGE ACT OF 1934. THESE FORWARD-LOOKING STATEMENTS ARE SUBJECT TO VARIOUS RISKS AND UNCERTAINTIES. THESE FACTORS INCLUDE, BUT ARE NOT LIMITED TO, THE ADVERSE IMPACT OF WEATHER CONDITIONS; UNSCHEDULED GENERATION OUTAGES, MAINTENANCE OR REPAIRS; UNANTICIPATED CHANGES TO FOSSIL FUEL OR GAS SUPPLY COSTS OR AVAILABILITY DUE TO HIGHER DEMAND, SHORTAGES, TRANSPORTATION PROBLEMS OR OTHER DEVELOPMENTS; DEVELOPMENTS IN THE FEDERAL AND STATE REGULATORY ENVIRONMENT AND THE TERMS ASSOCIATED WITH OBTAINING REGULATORY APPROVALS; COSTS ASSOCIATED WITH ENVIRONMENTAL LIABILITIES AND COMPLIANCE WITH ENVIRONMENTAL LAWS; THE RATE OF GROWTH AND ECONOMIC CONDITIONS IN OUR SERVICE AREAS AND THOSE OF OUR SUBSIDIARIES; THE SPEED AND DEGREE TO WHICH COMPETITION ENTERS OUR BUSINESSES; THE TIMING AND EXTENT OF CHANGES IN INTEREST RATES AND FLUCTUATIONS IN ENERGY-RELATED COMMODITY PRICES; RISKS ASSOCIATED WITH ACQUISITIONS, TRANSITION AND INTEGRATION OF ACQUIRED COMPANIES INCLUDING IMPLEMENTATION OF INFORMATION SYSTEMS AND REALIZING EFFICIENCIES IN EXCESS OF RELATED RESTRUCTURING CHARGES; CHANGES IN CUSTOMER USAGE PATTERNS AND PREFERENCES: REDUCTION IN MINORITY INTEREST BASIS REQUIRING US TO RECOGNIZE AN INCREASED SHARE OF ANY OPERATING LOSSES AT CERTAIN SUBSIDIARIES; OUR ABILITY TO RECOVER TRANSITION COSTS; APPROVAL OF OUR DEFAULT SUPPLY PORTFOLIO BY THE MPSC; ADVERSE CHANGES IN OUR CREDIT RATINGS; AS WELL AS CHANGING CONDITIONS OR DESCRIPTIONS IN THE ECONOMY, CAPITAL MARKETS AND OTHER FACTORS IDENTIFIED FROM TIME TO TIME IN OUR FILINGS WITH THE SEC THAT CAN BE LOCATED AT WWW.SEC.GOV AND REQUESTED FROM NORTHWESTERN CORPORATION. 1 <Page> NORTHWESTERN TEAM - -------------------------------------------------------------------------------- --------------- RICHARD HYLLAND PRESIDENT & COO --------------- - ------------------ ------------------- ------------------------ KIPP ORME MICHAEL HANSON ERIC JACOBSEN VP - FINANCE & CFO PRESIDENT & CEO COO, NORTHWESTERN GROWTH NORTHWESTERN ENERGY CORP. - ------------------ ------------------- ------------------------ 2 <Page> CREDIT HIGHLIGHTS - -------------------------------------------------------------------------------- - Extensive electric T&D network with strategic interconnections in WSCC and MAPP - Low-cost, efficiently operated gas distribution business in Nebraska, South REGIONAL UTILITY Dakota and Montana COMPANY - Vertically integrated utility in South Dakota with competitive fuel supply - Diversified customer base with minimal attrition due to low-cost rates - Low-risk regulated cash flow dominates - Over 77% of Recourse EBITDA(1) from regulated utility businesses STRONG AND PREDICTABLE CASH FLOW - Supportive regulatory framework in all three jurisdictions - Significant liquidity provided through $280 million revolving credit facility at NorthWestern (fully available) - Stable cash flow growth drives solid credit story - Capital expenditure program 100% funded by internal cash flow STABLE CREDIT PROFILE - Consistent de-leveraging with excess cash flow, growing to approximately $100 million per annum - Management committed to strong balance sheet quality and maintaining ratings (1) Recourse EBITDA measures cash flow available at NorthWestern Corporation to service recourse debt obligations. 3 <Page> NORTHWESTERN CORPORATION - -------------------------------------------------------------------------------- - FOUNDED IN 1923 - TODAY*... - $4.9 billion revenue - 2.5 million customers - 11,000 team members - More than 500 locations across all 50 states - FORTUNE 500 company - Focused on strong credit quality and core utility business - Streamlined business mix -divesting non-core segments (CornerStone) - CORPORATE STRUCTURE - Flat Structure: NSG is an operating division of NorthWestern and MPC will be once acquisition structure is collapsed in 2002 - NGC is a subsidiary of NorthWestern and is the holding company for the unregulated businesses [GRAPHIC OMITTED] S T R A T E G I C F O C U S --------------------------------- EXPANDING ENERGY MARKETS CONVERGING COMMUNICATIONS MARKETS --------------------------------- * COMPANY STATISTICS PRO FORMA FOR MONTANA POWER COMPANY ACQUISITION. 4 <Page> TRANSFORMING LOW RISK DISTRIBUTION ACQUISITION - -------------------------------------------------------------------------------- <Table> <Caption> --------------------------------------------- -------------------------------------------- EXTENSIVE SERVICE TERRITORY MANAGEMENT INTEGRATION --------------------------------------------- -------------------------------------------- _ Providing 589,000 customers with - Mike Hanson CEO, NorthWestern electric and natural gas service Energy (NSG and MPC) _ Covering the largest service territory - Entire senior management remains in in the upper Midwest including parts place at MPC of South Dakota, Nebraska and the - Collaboration team in place for past majority of Montana year to define integrated plan _ Built strong regulatory and political - Committed to executing best relationships practices - Common culture and customer focus BUILDS ON CORE COMPETENCY ---------------------------------------------------------------------- NORTHWESTERN IS AMONG THE LARGEST REGIONAL UTILITIES IN UPPER MIDWEST. ---------------------------------------------------------------------- </Table> 5 <Page> BUSINESS SEGMENTS <Page> NORTHWESTERN OVERVIEW - -------------------------------------------------------------------------------- ------------------- ELECTRIC OPERATIONS ------------------- - ---------------------------------- ---------------------------------- ELECTRIC DISTRIBUTION INTEGRATED ELECTRIC UTILITY - ---------------------------------- ---------------------------------- - - Montana based platform - South Dakota service territory - Low cost coal generation - - Default supplier obligation extended to 2007: Pass through - No nuclear exposure of supply costs - Over 57,000 customers - - Over 295,000 customers - Revenue mix by customer class: - Residential: 33% - - Revenue mix by customer class: - Commercial/ - Residential 28% Industrial: 43% - Commercial 34% - Wholesale: 21% - Industrial 38% - No individual customer accounts for more than 1% of revenues - - No individual customer accounts for more than 1% of revenues - Competitive rates vs. regional average - - Competitive rates vs. regional average ------------------------------ ----------------------------------- NORTHWESTERN GROWTH GAS OPERATIONS CORPORATION ------------------------------ ----------------------------------- ------------------------------ ----------------------------------- GAS DISTRIBUTION UNREGULATED BUSINESSES ------------------------------ ----------------------------------- - South Dakota, Nebraska and - Expanets Montana network - Leading provider of - Fuel cost adjustment clause networked communications, mitigates commodity exposure and data services and solutions to medium-sized - Over 236,800 customers businesses at customer premises - Customer mix - Significant recurring revenue - MPC: 156,000 customers base - NPS: 81,000 customers - Leading reseller of Avaya, Siemens, NEC, CISCO, IBM - Full customer choice in and other leading equipment Montana /technology suppliers - No material competition in - Blue Dot Nebraska and South Dakota - Residential and light- - No individual customer accounts commercial focused provider for more than 1% of revenues of HVAC services - CornerStone - Evaluating strategic options 6 <Page> FOCUS ON CORE REGULATED BUSINESS - -------------------------------------------------------------------------------- ------------------------------ 2001 PRO FORMA RECOURSE EBITDA ------------------------------ $297 MM* Electric Distribution 39.5% Gas Distribution 18.5% Integrated Electric 19.0% Unregulated 23.0% * EXCLUDES NET OTHER EBITDA, CORPORATE OVERHEAD AND SYNERGIES. 7 <Page> CONSERVATIVE CAPITAL EXPENDITURE PROGRAM FUNDED WITH INTERNAL CASH FLOW - -------------------------------------------------------------------------------- --------------------------------------------- 2001 PRO FORMA RECURRING CAPITAL EXPENDITURES --------------------------------------------- $101 MM NorthWestern Services Group 13.0% Unregulated* 29.0% Montana Power 58.0% * EXCLUDES CORNERSTONE. 8 <Page> ELECTRIC OPERATIONS - -------------------------------------------------------------------------------- [GRAPHIC OMITTED] Electric T&D Integrated Utility - - CUSTOMERS 352,400 - - T&D LINES 26,900 miles - - GENERATION 332 MW - - PEAK/AVERAGE DEMAND MT:1290 MW/932 MW SD:294 MW/150 MW - - ALLOWED ROE 10.75% (MT) 14.10% (SD) LOW-RISK, EFFICIENT ELECTRIC UTILITIES - - Balanced utility profile: MT is winter peak / SD is summer peak - - Strong operational track record: received Reliability One award from PA Consulting - - Extensive electric T&D network and interconnections with major transmission systems in WSCC and MAPP - - No competition in South Dakota - - Supportive regulatory environments ADEQUATE, PREDICTABLE POWER SUPPLY - - Default supplier term extended through 2007 - - Proposed default supply portfolio procured - - Existing generation in South Dakota covers peak load requirements - - Coal comprises 95% low-cost power supply in South Dakota - Average fuel costs have remained constant over last 3 years - No nuclear exposure - Coal from Powder River Basin 9 <Page> GAS OPERATIONS - -------------------------------------------------------------------------------- [GRAPHIC OMITTED] Montana Power Gas NPS Gas - - CUSTOMERS 236,800 - - DISTRIBUTION PIPELINES 7,300 miles - - TOTAL ANNUAL GAS MT 19,500,000 MMBtu THROUGHPUT: SD 5,500,000 MMBtu Neb. 5,600,000 MMBtu - - CITY GATE STATIONS 130 - - ALLOWED ROE 10.25% (SD, NE) 10.75% (MT) EFFICIENT AND LOW-COST GAS DISTRIBUTION SYSTEM - - Typically bundled service although transportation only service available for large commercial and industrial customers - - Strategic connections with 4 major non-affiliated transmission systems - Williston Basin Interstate - NOVA - Havre - Colorado Interstate - - Full retail choice in Montana _ Fuel tracking and cost pass through mitigates commodity exposure - - Supportive regulatory environment GAS DELIVERED THROUGH SHORT-AND LONG-TERM AGREEMENTS - - Own and operate 4 pipeline border crossings - - Firm contracts with Coast Energy Group and ONEOK Gas Marketing for gas supply in South Dakota and Nebraska - - Contracts with Canadian and Montana suppliers for MPC - - Own and operate 3 gas storage fields: 17.2 Bcf capacity 10 <Page> SUPPORTIVE REGULATORY ENVIRONMENTS - -------------------------------------------------------------------------------- - Electric market remains regulated - Deregulation not expected in near future SOUTH DAKOTA - Last electric rate case in April 1981 - Full pass-through of gas supply costs - $1.3 MM base gas rate increase in November 1999 - Transition to open retail markets - SB 390 effective in May 1997 - Recovery of unmitigated stranded costs is permitted MONTANA - Full cost recovery for default supplier - Default supplier status extended to July 1, 2007 - $16 MM electric / $4.3 MM gas rate increase in May 2001 - Annual gas cost adjustments with cost tracking and reconciliation - 25 year municipal franchises - Latest rate case issued for NPS in NEBRASKA April 2001 - Full pass through of gas supply costs ------------------------------------------------------------------------ STRONG RELATIONSHIPS WITH SOUTH DAKOTA, NEBRASKA AND MONTANA REGULATORS. ------------------------------------------------------------------------ 11 <Page> WELL STRUCTURED INVESTMENTS IN UNREGULATED BUSINESSES - -------------------------------------------------------------------------------- <Table> <Caption> - -------------------------------------------- --------------------------------------------- EXPANETS BLUE DOT - -------------------------------------------- --------------------------------------------- - - Leading mid-market provider of networked - Leading provider of air conditioning, communications and data services and heating, plumbing, and related services solutions - $424 million in 2001 revenues - - $1.0 billion in 2001 revenues - 850,000 customers in 29 states - Approximately 45% provided by recurring revenues - Customer base approximately 66% residential, 34% commercial - - 559,000 customers in 50 states - 3,500 employees - - Acquired Lucent's Growing and Emerging Markets ("GEM") division in 2000 - Preferred stock investment of $329 million as of 12/31/01 - - Significant integration and cost resizing initiatives completed in 2001 - 11% cash coupon - - Preferred stock investment of $314 million - More than 95% of equity vote and $51 million inter-company note as of 12/31/01 - Common stock warrants (40% of outstanding stock) - 12% cash coupon - Minimal minority interest loss allocation - More than 95% of equity vote expected in 2002 - Common stock warrants (40% of outstanding stock) - - Full minority interest loss allocation through 2001 - Minimal minority interest loss allocation expected in 2002 </Table> 12 <Page> OPERATIONAL EXCELLENCE PROGRAM WILL PROVIDE SUBSTANTIAL COST IMPROVEMENT - -------------------------------------------------------------------------------- - POSITION RESOURCES FOR MARGIN GROWTH WITHOUT COMPROMISING SERVICE EXCELLENCE TO OUR CUSTOMERS - IDENTIFY OPPORTUNITIES FOR IMPROVEMENT IN EFFICIENCY AND EFFECTIVENESS - Consolidating headquarters and other corporate functions - Combining back office and procurement functions: purchasing, travel, etc. - ANTICIPATE ANNUALIZED SAVINGS OF $150 MILLION BY END OF 2002 - Initiation of Operational Excellence Program covered by restructuring charge of $24.9 million in 2001 13 <Page> PRO FORMA CAPITALIZATION - -------------------------------------------------------------------------------- <Table> <Caption> ($ in millions) - ----------------------------------------------------------------------------------------------- PRO FORMA (1) MONTANA FINANCING FISCAL YEAR ENDED NORTHWESTERN POWER ADJUSTMENTS DECEMBER 31, 2001 - ----------------------------------------------------------------------------------------------- Cash $ 53.5 $ 62.2 -- $ 115.7 CAPITALIZATION: Recourse Debt Unsecured 366.1(2) 40.0 340.0 746.1 Secured 141.4 406.1 -- 547.5 - ----------------------------------------------------------------------------------------- Total Recourse Debt $ 507.5 $ 446.1 $ 340.0 $ 1,293.6 Preferred Stock 309.0 41.9 -- 350.9 Shareholders' Equity 396.4 -- 200.0 596.4 - ----------------------------------------------------------------------------------------- Total Capitalization $ 1,212.9 $ 488.0 $ 540.0 $ 2,240.9 RATIOS: Net Recourse Debt 55.4% Preferred Stock 16.5% Equity 28.1% - ----------------------------------------------------------------------------------------- Total 100.0% ========================================================================================= </Table> (1) Adjusted for debt reduction associated with $200 million equity offering during 2002 and receipt of $97 million in proceeds from the sale of Colstrip. (2) Includes $93 million of guaranteed non-recourse debt. 14 <Page> PRO FORMA CASH FLOW PROFILE - -------------------------------------------------------------------------------- <Table> <Caption> PRO FORMA (1) FISCAL YEAR ENDED ($ in millions) NORTHWESTERN MONTANA POWER DECEMBER 31, 2001 - ------------------------------------------------------------------------------------------------------ INCOME/CASH FLOW ITEMS: Utility EBITDA $ 66.8 $ 160.2 $ 227.0 Unregulated Subsidiary Dividends on NOR Preferred Stock Investment 68.6 -- 68.6 Other -- 3.1 3.1 Corporate Overhead (17.0) -- (17.0) Operational Excellence/Integration Synergies 15.0 -- 15.0 - -------------------------------------------------------------------------------------------------- Total Recourse EBITDA $ 133.4 $ 163.3 $ 296.7 EBIT $ 223.6 FFO $ 148.2 Interest Expense - Recourse Debt(1) $ 98.4 RATIOS: EBITDA/Interest 3.0x (EBITDA - Capex)/Interest 2.0x EBIT/Interest 2.3x FFO Interest Coverage 2.5x Debt/EBITDA(1)(2) 4.4x ================================================================================================== </Table> (1) Adjusted for debt reduction associated with $200 million equity offering during 2002 and receipt of $97 million in proceeds from the sale of Colstrip. (2) Recourse debt plus $93 million of guaranteed non-recourse debt. 15 <Page> ACCOUNTING FOR UNREGULATED SUBSIDIARIES - -------------------------------------------------------------------------------- <Table> <Caption> - ---------------- ------------ ----------- --------------- -------------------- --------------------------- -------------- NOR EXISTING COMMON ALLOCATION OF NORTHWESTERN EQUITY VOTING LOSSES/PROFITS TO NORTHWESTERN INCOME INTEREST INTEREST CONSOLIDATION MINORITY HOLDERS INVESTMENT RECOGNITION - ---------------- ------------ ----------- --------------- -------------------- --------------------------- -------------- EXP@NETS 0% 95% 100% 2001: ($128) MM - 12% coupon Preferred non-convertible Dividend 2002 & Beyond: preferred $11 MM available - Series B Common - Common Stock Warrants (40% of Outstanding Stock) - ---------------- ------------ ----------- --------------- -------------------- --------------------------- -------------- BLUEDOT. 0% 95% 100% 2001: ($13.7) MM - 11% coupon Preferred non-convertible Dividend 2002 & Beyond: preferred $0 MM available - Series B Common - Common Stock Warrants (40% of Outstanding Stock) - ---------------- ------------ ----------- --------------- -------------------- --------------------------- -------------- </Table> - -------------------------------------------------------------------------------- STRUCTURE ALLOCATED NET LOSSES/PROFITS TO MINORITY INVESTORS WHILE MINIMIZING RISK TO NORTHWESTERN. - -------------------------------------------------------------------------------- 16 <Page> ON-GOING CREDIT SUPPORT - -------------------------------------------------------------------------------- _ CASH FLOW GROWTH - Integration synergies between MPC and NSG - Realization of significant savings from Operational Excellence Program: $150 million per annum by end of 2002 - Customer growth at distribution and electric utility businesses _ STABLE CAPITAL PROGRAM - Utility maintenance CapEx remains essentially flat at approximately $72 million - Completely internally funded - Minimal additional investment / maintenance CapEx in unregulated subsidiaries _ SIGNIFICANT DEBT REDUCTION - Free cash flow applied to debt repayment: increasing to approximately $100 million per annum - Additional $200 million equity issuance planned to be completed during 2002 _ LIQUIDITY ACCESS - Long dated maturity profile of outstanding debt: Average maturity over 20 years - $280 million working capital facility (currently undrawn) 17 <Page> INVESTMENT HIGHLIGHTS - -------------------------------------------------------------------------------- _ STRONG UNDERLYING LOW RISK REGULATED UTILITY CASH FLOW, STEADY GROWTH _ FOCUS ON FUTURE GROWTH IN REGULATED UTILITY BUSINESS _ FREE CASH FLOW AND EQUITY ISSUANCE APPLIED TO THE REPAYMENT OF DEBT _ SIGNIFICANT SYNERGIES AND EFFICIENCY IMPROVEMENTS _ MODEST ANTICIPATED CAPITAL EXPENDITURES FUNDED FROM INTERNAL CASH FLOW _ MANAGEMENT COMMITTED TO STRONG CREDIT QUALITY 18